Wave In V1 Research Articles

Comparative study of the surface and endocavitary signals of cardiac pacing system analyzers with respect to the conventional polygraphy systems signals during implantation of conduction system pacing

Abstract Introduction and objectives Left bundle branch area pacing (LBBAP), is a novel modality of physiologic pacing that requires an adequate assessment of the endocardium as well as the body-surface electrocardiographic signals for a successful pacing-lead implantation. We aimed to assess if LBBAP criteria(1), specifically left ventricular septal pacing (LVSP) and left bundle branch pacing (LBBP) criteria, can be satisfactory measured using the signals resulting from different cardiac pacing analyzers (PSAs) by comparing them to the ‘conventional’ signals obtained from multichannel polygraph systems (MPSs) during the implantation procedure. Methods Comparative observational, prospective, multicenter study of consecutive patients who underwent a LBBAP strategy as first intention. LBBP was defined in the presence of a paced QRS with right bundle branch morphology in V1 (initial r wave in lead V1) and at least one of the following criteria: 1. V6-R-Wave Peak Time (RWPT) < 80 ms. 2. V1–V6 interpeak interval > 33 ms. 3. QRS transition from non-selective left bundle branch pacing to selective left bundle branch pacing or NS-LBBP to left ventricular septal pacing during pacing threshold. 4. Sudden increase of V6-RWPT > 15 ms because of reducing pacing output. 5. Left bundle potential-V6RWPT = stim-V6RWPT (±10 ms). For patients without initial r wave in V1, LBBP was considered in the presence of QRS transition during pacing. LVSP was defined by a paced QRS showing a typical terminal R-wave in V1, anatomical position of the lead in the left ventricular septum documented by fluoroscopy and not fulfilling the additional criteria previously described for LBBP. Results 63 patients were included. The basal characteristics of the patients are shown in Figure I. No significant differences (p<0.96) were observed in the basal QRS between the MPSs (129±29ms) and the PSAs (129±28ms). Initial "W" morphology in V1 during initial pacing was obtained in 90% of patients, without differences between both measurement systems. There were no significant differences between the MPSs and the PSAs in the paced QRS in V1 (140±10ms vs 141±12ms, p<0.746) nor in V6 (127.4±13ms vs 128.2±14.6ms, p<0.96). The measurement of the R wave peak time (RWPT) in V6 was 78.3±15ms vs 77±14 ms (p<0.72), and the V1-V6 inter-peak was 41.1±16ms in the MPSs vs 39±16 ms the PSAs (p<0.6), respectively, the Pearson correlation coefficients for these last two measurements being 0.91 (p <0.0001) and 0.91 (p <0.0001) (Figure II). Finally, according to electrocardiographic criteria measured by the MPSs, LBBP was achieved in 69% of patients, accomplishing 31% of the patients LVSP criteria, being the same proportions observed when PSAs measures where applied. Conclusions The signals resulting from the different PSAs can be useful to assess septal as well as LBBP criteria as an alternative to the ‘conventional’ signals obtained from MPSs.

Electrocardiographic criteria for the diagnosis of left ventricular hypertrophy in patients with severe aortic stenosis

Abstract Introduction There is a lack of data regarding the performance of current electrocardiographic (EKG) criteria for left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). Purpose To test the performance of the current EKG scores to diagnosis LVH in AS patients, and also to compare the performance of a new proposed score. Methods The present study evaluated 80 patients with severe AS that underwent cardiac magnetic resonance to diagnose LVH, defined as left ventricular indexed mass of 95 g/m² for female and 115 g/m² for male patients. The EKG criteria used for left ventricular hypertrophy were Sokolow-Lyon criteria, Romhilt-Estes point score system, Cornell voltage criteria and Peguero-Lo Presti criteria. Results Among the 80 patients included in analysis, 58.7% were male and the mean age was 64±8 years. There was a high prevalence of comorbidities, highlighting diabetes (32.5%), hypertension (67.5%), atrial fibrillation (5.0%) and coronary artery disease (11.3%). Regarding echocardiogram, the median left ventricle ejection fraction was 64 (56-68)% and the median indexed aortic valve area was 0.43 (0.35-0.49) cm²/m². Cardiac magnetic resonance analysis demonstrated a mean left ventricle mass of 168±55g, and the LVH incidence was 26.3%. Regarding EKG, Strain pattern was found in 49.1% of the patients, Cornell voltage criteria was positive in 51.3%, Sokolow-Lyon criteria in 51.3%, Romhilt-Estes point score system in 42.5% and Peguero-Lo Presti criteria in 61.3%. Discriminative capacity of electrocardiographic criteria for LVH is shown in Figure 1. Peguero-Lo Presti score had the best diagnostic accuracy in the overall population and in male sex (AUC 0.776), while Cornell voltage criteria had the best diagnostic accuracy in female patients (AUC 0.776). Based on linear regression model, the proposed score was created to predict LVH at cardiac magnetic resonance: 48 + (1.3 x Deepest S wave) + (0.5 x S wave in V1 or V2 plus R wave in V5). The proposed score cutoff value of 90.5 mm had a sensitivity of 0.765 and specificity of 0.707 (for male sex: 0.769 and 0.655, respectively; for female sex: 0.750 and 0.759, respectively). Compared to the scores described in the literature, the proposed score had the best area AUC for the overall population (Figure 1), for female and male patients (AUC 0.796, 0.819 and 0.780, respectively). Conclusion In patients with severe AS, the proposed score had the best diagnostic accuracy compared to the scores described in the literature for LVH identification, followed by Peguero-Lo Presti score, even when analyzed based on gender. Besides, the proposed score had also acceptable sensitivity and specificity for LVH detection.AUC of electrocardiographic scores.

Fine Tuning ECG Interpretation for Young Athletes: ECG Screening Using Z-score-based Analysis

BackgroundElectrocardiograms (ECGs) in athletes commonly reveal findings related to physiologic adaptations to exercise, that may be difficult to discern from true underlying cardiovascular abnormalities. North American and European societies have published consensus statements for normal, borderline, and abnormal ECG findings for athletes, but these criteria are not based on established correlation with disease states. Additionally, data comparing ECG findings in athletes to non-athlete control subjects are lacking. Our objective was to compare the ECGs of collegiate athletes and non-athlete controls using Z-scores for digital ECG variables to better identify significant differences between the groups and to evaluate the ECG variables in athletes falling outside the normal range.MethodsValues for 102 digital ECG variables on 7206 subjects aged 17–22 years, including 672 athletes, from Hawaii Pacific Health, University of Hawaii, and Rady Children’s Hospital San Diego were obtained through retrospective review. Age and sex-specific Z-scores for ECG variables were derived from normal subjects and used to assess the range of values for specific ECG variables in young athletes. Athletes with abnormal ECGs were referred to cardiology consultation and/or echocardiogram.ResultsAthletes had slower heart rate, longer PR interval, more rightward QRS axis, longer QRS duration but shorter QTc duration, larger amplitude and area of T waves, prevalent R’ waves in V1, and higher values of variables traditionally associated with left ventricular hypertrophy (LVH): amplitudes of S waves (leads V1-V2), Q waves (V6, III) and R waves (II, V5, V6). Z-scores of these ECG variables in 558 (83%) of the athletes fell within − 2.5 and 2.5 range derived from the normal population dataset, and 60 (8.9%) athletes had a Z-score outside the − 3 to 3 range. While 191 (28.4%) athletes met traditional voltage criteria for diagnosis of LVH on ECG, only 53 athletes (7.9%) had Z-scores outside the range of -2.5 to 2.5 for both S amplitude in leads V1-V2 and R amplitude in leads V5-6. Only one athlete was diagnosed with hypertrophic cardiomyopathy with a Z-score of R wave in V6 of 2.34 and T wave in V6 of -5.94.ConclusionThe use of Z-scores derived from a normal population may provide more precise screening to define cardiac abnormalities in young athletes and reduce unnecessary secondary testing, restrictions and concern.

The Vectorcardiogram Characteristic and Its Predictive Value for Reduced Left Ventricular Ejection Fraction of Children with Duchenne Muscular Dystrophy.

The prognosis of Duchenne muscular dystrophy (DMD) is poor once it develops to the stage of cardiac impairment. Recent studies have demonstrated that electrocardiogram (ECG), which consists of general ECG and vectorcardiogram (VCG), retains an extremely powerful role in the assessment of patients with reduced left ventricular (LV) systolic dysfunction. However, data regarding VCG recordings in DMD and its prognostic value for reduced left ventricular ejection fraction (LVEF) of DMD have never been reported. This study aims to describe the characteristics of VCG in children with DMD and to explore the predictive value of VCG for reduced LVEF in children with DMD. A total of 306 patients with a known diagnosis of DMD confirmed by the genetic test were retrospectively enrolled at our hospital between August 2018 and August 2022. This resulted in a total study group of 486 VCG recordings. Among them, 75 DMD patients who underwent cardiac magnetic resonance (CMR) later after one year follow-up were prospectively enrolled. The trend of VCG parameters of DMD patients across the different age span were compared with age-matched normal children. Concordance statistic analysis was further performed to assess the validity of VCG parameters in predicting the occurrence of reduced LVEF in patients with DMD. DMD patients have a significantly higher heart rate, R waves in V1, QRS loop percentage in the right anterior quadrant in the horizontal plane (horizontal quadrant II) and QRS loop percentage in the anterior superior quadrant in the sagittal plane (sagittal quadrant IV) than normal children. Concordance statistic (C-statistic) showed an area under the curve of quadrant IV in the sagittal plane of baseline was 0.704. The receiver operating characteristic (ROC) curve shows that quadrant IV in the sagittal plane of 7.57% was the optimal cutoff with a sensitivity of 53.3% and a specificity of 88.3% for predicting reduced LVEF in DMD patients. Our study firstly showed that QRS loop percentage in the right anterior quadrant in the horizontal plane (horizontal quadrant II) and QRS loop percentage in the anterior superior quadrant in the sagittal plane (sagittal quadrant IV) could be abnormal in DMD boys as early as before 5 years old. Evaluation of the myocardium by VCG in the early age to predict possible cardiac systolic dysfunction may have important implications for the ongoing management of DMD boys.

Deep septal pacing for pacemaker-induced cardiomyopathy

Abstract Background Conventional right ventricular pacing can impair left ventricular function and cause heart failure, known as pacing induced cardiomyopathy (PICM). Upgrade to cardiac resynchronization therapy (CRT) is the most common treatment for PICM. Recently, left bundle branch area pacing (LBBAP) has emerged as a potential alternative both to conventional RV pacing and to CRT. In Deep septal pacing (DSP), a simplified alternative to LBBAP, the lead is inserted deep in the septum, does not reach the subendocardial area, but is still able to achieve narrower paced QRS than during conventional pacing. Purpose The aim of this study was to assess the effect of DSP in a cohort of patients with PICM. Methods We included consecutive patients diagnosed with PICM who were referred to our unit between January 2020 and January 2022 for a device upgrade. The aim was to upgrade patients to DSP. In the absence of terminal R wave in V1, the procedure was considered successful if a paced QRS duration ≤140 ms was obtained. Clinical and device follow-up were performed one and 6 months after the procedure, and echocardiography at 6 months. The study was approved by the Clinical Research Ethics Committee and all patients signed informed consent. Results Fifteen patients were recruited during the study period. One patient was excluded because a QRS ≤ 140 ms could not be achieved, and 2 other patients because a terminal R wave in paced QRS in V1 was obtained. The characteristics of the 12 included cases are detailed in Table 1. The mean LVEF was 33% (SD 4%) and the mean percentage of RV pacing was 99% (SD 1%). All patients had symptomatic heart failure. Non stylet-driven electrodes were used in 8 of the 12 patients. Acute threshold was < 1V - 0’4 ms in all, and remained stable during follow-up. No procedure-related complications or lead dislodgements were detected. The mean paced QRS duration with RV pacing was 172 ms (SD 14 ms) whereas after the upgrade it was 130 ms (SD 7 ms). As compared to RV pacing, DSP was associated with a significant reduction in paced QRS duration (mean difference 41 ms, p<0.001). As shown in Table 1, after DSP all patients except one (11/12, 92%) experienced an increase in LVEF of at least 10%; five patients (42%) achieved an LVEF>50%. The mean LVEF after the upgrade was 46% (SD 9%). The mean improvement in LVEF with DSP was 13% (SD 10%). Conclusions In patients with PICM, deep septal pacing achieves narrower QRS as compared to RV pacing and is associated with a significant improvement in LVEF. Deep septal pacing might be an effective and simpler alternative to biventricular or left bundle branch pacing in patients with PICM.Table 1

AN ISOLATED ACUTE RIGHT VENTRICULAR INFARCTION

Abstract Isolated right ventricular infarction occurs only in about 3% of the overall myocardial ischemic episodes. Clinical presentation is often insidious and variable case by case. The correct diagnosis is therefore crucial for a proper management, and a good prognosis in the short and long term. A 72–year–old patient suffering from arterial hypertension went to the emergency room of our hospital for malaise and asthenia for about 12 hours that have increased in 3–4 hours before the arrival. He was sweating, tachypneic with normal value of the oxygen saturation to the finger (SpO2:96%), with arterial hypotension (pressure values = 85/50 mmHg), turgor of the jugular veins in the absence of peripheral edema. Cardiac examination revealed no pathological noises and lung examination revealed clear lung fields. Electrocardiogram showed sinus tachycardia at a rate of 118 bpm, second degree atrioventricular (AV) block 2:1 type and an AV conduction delay with a first–degree AV block (P–Q interval: 320–330 msec). A pulmonary P wave was present and the QRS complex showed predominant R waves in V2–V3 with slight repolarization abnormalities (figure, panel A). An ST–elevation in right precordial leads, V3R and V4R was evident. (figure, panel B). Echocardiographic evaluation showed a hypertrophic left ventricle with normal volume and function, with marked enlarged right sections (figure, panels C–H). Moreover, we can observe the flattening of the interventricular septum with a D shaped left ventricle. Septal flattening occurred only in diastole, expression of RV volume overload (figure, panels F–H). After taking 180 mg of ticagrelor administrated orally and 150 mg of aspirin intravenously, the patient was immediately transferred to the catheterization laboratory for emergency coronary angiography. Coronary angiography highlighting an ostial thrombotic obstruction of a co–dominant right coronary artery (RCA) in the absence of significant stenosis of the left coronary circulation (figure, panels I–M). Primary percutaneous coronary intervention of RCA was performed with STENT implantation with a good postoperative result. (figure, panels L). During the hospital stay, the patient showed a good clinical status without any CV events, with progressively normalization of electrocardiographic abnormalities and persistent sinus rhythm. He was discharged after ten days.

MYOCARDIAL INFARCTION DUE TO LEFT CIRCUMFLEX ARTERY OCCLUSION: A SUBTLE TROJAN HORSE

Abstract A 47–year–old man presented to the emergency department complaining of recurrent chest pain (CP) since the previous day. His medical history included active smoking and dyslipidemia. The ECG revealed sinus bradycardia (56 bpm) with widespread ST elevation, consistent with benign early repolarization, and hyperacute and broad–based T waves in V2–V3 (Fig. A). The echocardiography showed normal left and right ventricular systolic function and no valvular abnormalities. A low but abnormal initial high–sensitivity cardiac troponin I value (40 pg/mL, normal range: 1.7– 34,2 pg/mL) and a slightly and early increase after two hours (52 pg/ml) were seen. Therefore, the patient was admitted to our intensive cardiac care unit (ICCU) with a working diagnosis of non–ST–segment elevation myocardial infarction (NSTEMI). No sign or symptoms of heart failure on physical examination were recorded. GraceScore 2.0 was calculated as 68 points and coronary angiography was organized within 24h. Two hours after admission to the ICCU, the patient experienced a new episode of CP. Consequently, ECG and echo were repeated. Compared to the previous results, ECG showed dynamic changes in V2–V3, with the resolution of hyperacute T waves (Fig B); bedside echo remained unchanged. Considering the unresponsiveness to nitrate therapy, the cath lab was activated for a time–dependent coronary angiography. The exam showed an acute total thrombotic occlusion of the mid–segment of the circumflex branch (LCx) in the setting left–sided dominant circulation. A drug eluting stent was deployed into the culprit lesion (Fig. C), and the coronary flow was restored completely (TIMI Flow 3). The subsequent hospital stay proceeded without complications. The peak troponin level was 60’000 pg/ml. The patient was discharged on the fifth day, asymptomatic and hemodynamically stable, with instructions to continue dual antiplatelet therapy. The case report focuses on the electrocardiographic and angiographic expression of LCx total occlusion. Despite acute myocardial infarction (AMI) size was large, as confirmed by the abnormal troponin I values and the angiographic total occlusion, the first and the repeated ECGs showed only vague repolarization changes without clear ST–segment modifications. LCx occlusion is often characterized by the absence of significant ST–elevation, therefore categorized as NSTEMI. Greater awareness of the presentation of LCx–related AMI can be crucial to avoid delays in reperfusion.

A 20–YEAR FOLLOW–UP OF SUCCESSFUL SURGICAL MANAGEMENT OF DOUBLE–OUTLET RIGHT VENTRICLE WITH PULMONARY STENOSIS: A CASE REPORT

Abstract A 25–year–old man, suffering from worsening exertional dyspnea for 4 months, was referred to our Cardiology Unit. The patient was previously diagnosed with a late diagnosis of double outlet right ventricle (DORV), as well as pulmonary stenosis, VSD, and right–sided aortic arch for which he underwent a first surgical procedure around the age of 2 involving an intersternal anastomosis through a left lateral thoracotomy approach. A second intervention took place 2 years later for a radical correction of the anomaly through a median sternotomy. The patient had sporadic follow–up since then. A baseline ECG was performed, showing evidence of sinus rhythm, normal AV with a bifid P wave in lead II, slight RAD, incomplete RBBB, and asymmetric negative T waves from V1 to V3 and in aVL, and biphasic T waves in V4–V5. We performed an echocardiogram which showed: a dilated RA, a normal–sized LA, an apparently intact interatrial septum without evident shunts; a normal sized LV; EF 60%; a moderately dilated, hypertrophic and hypertrabeculated RV; FAC 33%; normal aortic flow; a minimal MR; a massive residual pulmonary insufficiency; a moderate TR; a dilatated pulmonary trunk; a normal–sized and collapsible IVC upon inspiration; PAPs of 70 mmHg; no pericardial effusion. A maximal exercise stress test appeared to be normal throughout. However, due to the severe pulmonary hypertension he was referred to our PH centre. While these patients are commonly affected by residual early or late left ventricular outflow tract obstruction, fortunately our patient was not. DORV is a relatively common congenital heart defect characterized by an abnormal connection between the ventricles and arteries, in which both the aorta and the pulmonary trunk are connected completely or predominantly to the right ventricle. The anatomical spectrum of this anomaly is quite large, and it can be associated with the presence of a VSD that often extends towards one or both of the arterial valves, allowing the flow of blood from the left ventricle to the aorta. An accurate diagnosis through echocardiography or CMR is essential in order to guide the surgical repair and the appropriate therapeutic approach for individuals affected by this anomaly. A successful surgical correction of DORV is essential, but it is important to be aware of the potential complications of post–operative PH (especially in patients with preoperative PH), which necessitates close surveillance and appropriate therapeutic management.

LEFT BUNDLE BRANCH BLOCK AND ACUTE CORONARY SYNDROME: WHAT IS THE ROLE OF MODIFIED SGARBOSSA–SMITH CRITERIA AND THE WELLENS‘ PATTERN?

Abstract A 55–year–old man presented to the emergency room with intermittent chest pain that started the day before. His medical history included hypertension, and dyslipidemia. The initial electrocardiogram (ECG) showed sinus rhythm (75 bpm) with pre–existing left bundle branch block (LBBB), without modified Sgarbossa–Smith criteria, despite the hyperacute appearance of T waves in V2–V4 (Fig. 1). Additionally, there were alterations in ventricular repolarization in the lateral region, morphologically not fully justifiable by the mentioned conduction delay. Echocardiography revealed normal left and right ventricular systolic function and no valvular abnormalities. Laboratory tests showed a pathological release of myocardial necrosis enzymes, with a typical rise–and–fall curve (10 pg/mL, 100 pg/mL, 200 pg/mL; normal range: 1.7–34.2 pg/mL). Therefore, the patient was admitted to the intensive cardiac care unit (ICCU) with a working diagnosis of non–ST–segment elevation myocardial infarction (NSTEMI). There were no recurrent angina episodes or signs/symptoms of heart failure on physical examination. During hospitalization, ECG and echocardiography were repeated. The follow–up ECG (12 hours after admission) showed persistent LBBB with biphasic T waves in leads V2–V5 with slight negative deflection at the end. This T wave abnormality can be interpreted as Wellens’ ECG Type A (Fig. 3A). The echocardiogram remained unchanged. Consequently, the catheterization lab was activated for urgent coronary angiography. The examination revealed subocclusion of the mid–segment of the left anterior descending artery (LAD). A drug–eluting stent was deployed in the culprit lesion (Fig. 2), restoring coronary flow completely (TIMI Flow 3). The subsequent hospital stay proceeded without complications. The ECG performed before discharge showed a typical LBBB, with normalization of T waves in precordial leads (Fig 3B). The presented case is about ECGs containing a pre–existing LBBB pattern in a patient with chest pain. The modified Sgarbossa–Smith criteria were not met in either the first recorded ECG or the second, whereas Wellens’ signs were detectable. Wellens’ syndrome can be diagnosed in a case of LBBB and help detect a high–grade LAD stenosis even if modified Sgarbossa–Smith criteria are not met.

WELLENS SYNDROME: TIMELY RECOGNITION AND SUCCESSFUL REVASCULARIZATION

Abstract Wellens syndrome is a condition characterized by clinical and instrumental signs suggestive of a critical proximal left anterior descending (LAD) coronary artery stenosis and requires early revascularization. Diagnostic criteria include T–wave changes in ECG during asymptomatic periods in patients with a history of chest pain, absence of significant cardiac enzyme movement, no ST–segment elevation, preserved R–wave, and no pathological Q waves. Early recognition of this syndrome is crucial, due to its 10–15% prevalence, allowing proper management and myocardial function recovery, avoiding potentially catastrophic outcomes. A 64–year–old male, with hypertension, undiagnosed diabetes, and family history of CAD, presented to our ER with sudden, brief chest pain radiating to the left upper limb. Similar episodes had occurred in the past week. The patient denied previous cardiovascular events and home therapy. ECG conducted by the attending cardiologist, during free chest pain period, showed biphasic T–wave in V1–V3 (a). Admission ECG resembled the ambulatory one. Lab results: Hb 14.7 g/dl, Troponin I 0.059 ng/ml (cut–off 0.034). Echocardiogram indicated distal septum akinesia. Urgent coronary angiography was performed, detecting subocclusive stenosis in the proximal–mid LAD. Successful revascularization was achieved by PTCA and implantation of 1 DES. (b) Subsequently, the patient was admitted to the Cardiac Intensive Care Unit for multiparametric monitoring. The ECG showed deeply negative T waves from V1 to V6. (c) No complications during hospitalization. Discharge ECG showed repolarization anomalies improvement. Echocardiography revealed preserved systolic function, without global or segmental anomalies in wall motion. Wellens syndrome is a manifestation of acute coronary syndrome that precedes an anterior wall MI. This condition can be identified by its characteristic T–wave patterns on ECG. Patients with this syndrome have severe LAD occlusion and require early coronary intervention. In chest pain episodes, the ECG appears normal, and troponin levels often remain within the normal range, which can potentially provide false reassurance. Wellens syndrome is a cardiac emergency requiring immediate attention; it is crucial for the physician to promptly identify the typical ECG signs of Wellens Syndrome, facilitating early coronary revascularization to prevent adverse patient outcomes.

HALF DOSE THROMBOLYSIS IN INTERMEDIATE – HIGH RISK PULMONARY EMBOLISM WITH TRICUSPID VALVE MOBILE MASS: A BAIL OUT STRATEGY

Abstract A 82–year–old previously healthy male was referred to the emergency department complaining sudden onset dyspnea and witnessed syncope complicated by head trauma. Recurrent dizziness occurred previously. No history or drug consumption noted. On admission: heart rate 90 beats/min, blood pressure 110/60 mmHg, respiratory rate 25 breaths/min, oxygen saturation 87% in room air, normal body temperature. No lower extremities tenderness or swelling reported. Consistent with peripheral blood oxygen saturation levels, arterial blood gas analysis showed hypoxemia and respiratory alkalosis. Laboratory exams were significant for thrombocytopenia (89.000 cells/L), elevated cardiac troponin T levels (222 ng/L) and natriuretic peptide (NT pro–BNP 3944 pg/mL). Head CT excluded acute cerebral hemorrhage. At the electrocardiogram, signs of RV strain were present (biphasic T–waves in V1–V3 leads, S1–Q3–T3). Transthoracic echocardiography (TTE) showed dilated RV with hypokinetic free wall, “D–shaped” LV, “60/60” sign and a mobile filiform mass crossing the tricuspid valve plan in the right atrium (fig. 1). The patient did not present structural valvular abnormalities or endocarditis–related risk factors. CT pulmonary angiography detected a “saddle” PE and extensive thrombosis in inferior vena cava. After unfractioned heparin (UFH) bolus, the patient was transferred to our intensive care unit and balancing risks and benefits the chosen treatment option consisted in half dose systemic thrombolysis (50 mg rtPA in 60’’; 10 mg as loading dose in 2’). Because of potential harmful effects in thrombocytopenia and recent head trauma, UFH was temporarily withheld and started again after 1 hour. The day after, a beside TTE showed complete tricuspid thrombus resolution, a significant decrease in RV/LV ratio and systolic pulmonary artery pressure (fig. 2). Apart from small hematomas, no bleedings were reported. The patient was shifted to the ward on the next day and following course was uneventful. On day 4 a direct oral anticoagulant (Dabigatran 110 mg) was started. Abdominal and inferior limb–deep–venous ultrasound were both negative for pathological reports. A total body CT was scheduled to exclude silent malignancies at discharge. Take home message: in intermediate–high risk PE, half dose systemic fibrinolysis strategy is controversial since its potential benefit is counterbalanced by concerns about major bleedings, but increasing data suggest its efficacy with low risk profile.

Deep terminal negative of the P wave in V1 and incidence of ischemic stroke: The atherosclerosis risk in communities (ARIC) study

BackgroundDeep terminal negative of the P wave in V1 (DTNPV1) is a marker of left atrial remodeling. We aimed to evaluate the association of DTNPV1 with incident ischemic stroke. MethodsThe Atherosclerosis Risk in Communities study is a prospective community-based cohort study. All participants at visit 4 (1996–1998) except those with prevalent stroke, missing covariates, and missing or uninterpretable ECG were included. DTNPV1 was defined as the absolute value of the depth of the terminal negative phase >100 μV in the presence of biphasic P wave in V1. Association between DTNPV1 as a time-dependent exposure variable and incident ischemic stroke was evaluated. The accuracy of the prediction model consisting of DTNPV1 and CHA2DS2-VASc variables in predicting ischemic stroke was analyzed. ResultsAmong 10,605 participants (63 ± 6 years, 56% women, 20% Black), 803 cases of ischemic stroke occurred over a median follow-up of 20.19 years. After adjusting for demographics, DTNPV1 was associated with an increased risk of stroke (HR 1.96, [95% CI 1.39–2.77]). After further adjusting for stroke risk factors, use of aspirin and anticoagulants, and time-dependent atrial fibrillation, DTNPV1 was associated with a 1.50-fold (95% CI 1.06–2.13) increased risk of stroke. When added to the CHA2DS2-VASc variables, DTNPV1 did not significantly improve stroke prediction as assessed by C-statistic. However, there was improvement in risk classification for participants who did not develop stroke. ConclusionDTNPV1 is significantly associated with higher risk of ischemic stroke. Since DTNPV1 is a simplified electrocardiographic parameter, it may help stroke prediction, a subject for further research.

Different degrees of anterior displacement of QRS complex

Electrocardiogram of a patient affected by hypertrophic cardiomyopathy showed normal PR and QRS intervals and signs of left ventricular hypertrophy. In leads I,V5 and V6 the initial q waves were absent. A subsequent electrocardiogram revealed the appearance of prominent anterior QRS forces expressed by a change from rS to R pattern in leads V2 and V3 with a tall R wave in V2. PR and QRS intervals and QRS axis remained substantially unchanged. Other electrocardiograms showed day-to-day variations of the anterior displacement of QRS complex. The different degrees of anterior displacement appear to be an expression of an underlying left septal fascicular block, but a diagnosis cannot be made with certainty.

Electrocardiographic and Autonomic Nervous System Changes after Changes in the Posture of Children and Adolescents with Duchenne Muscular Dystrophy.

Duchenne Muscular Dystrophy (DMD) is a rare inherited neuromuscular disease. At first, cardiac involvement may be asymptomatic. Therefore, assessing patients using non-invasive methods can help detect any changes. Analyze the electrocardiogram (ECG) test and heart rate variability (HRV) of the DMD group and compare the information with that of the age-matched control group. A prospective study with 27 male patients with DMD (11.9 years old), who underwent clinical evaluation, ECG, echocardiogram, and Holter monitoring. ECG (200% increase) was assessed by two independent observers. HRV was measured over time (24 h) and in the frequency domain, in the supine and sitting positions. The healthy group consisted of nine patients (11.0 years old). A value of p < 0.05 was considered statistically significant. The mean ejection fraction (EF) was 60% (34 to 71%). The Kappa coefficient for ECG measurements ranged from 0.64 to 1.00. An increase in the R/S ratio in V1 was observed in 25.9% of the subjects, pathological Q wave in 29.6%, and fragmented QRS in 22.2% in inferior/high lateral regions, with a negative correlation with EF (p = 0.006). There was low HRV, without the influence of any variable, including treatment. With the change in position, there was an increase in HR (p = 0.004), but there was no change in HRV. The LF/HF ratio was 2.7 in the DMD group and 0.7 in the control group (p = 0.002). In DMD subjects, prominent R waves in V1 and changes in the inferior/high lateral regions occurred in almost 30% of the cases. Lower vagal tone was observed without the influence of the variables age, ejection fraction, QT dispersion, and treatment. Despite the increase in HR, there was no adequate HRV response to the change in position.

Estimating Left Ventricular Mass from the Electrocardiogram across the Spectrum of LV Mass from Normal to Increased LV Mass in an Older Age Group.

To examine the relationship of QRS voltages and left ventricular (LV) mass across the spectrum of individuals with different LV mass. Twenty QRS voltage measurements or combinations were determined in a consecutive series of 159 adults with an ECG and echocardiogram without previous myocardial infarction, left or right bundle branch block, pre-excitation, or electronic pacemaker. The four strongest and significant correlations between QRS and LV mass were S in V4, deepest S wave in any precordial lead plus S in V4, S in V3, and S in V3 plus R in AVL times QRS duration. For men, the strength of the relationships were S in V3 (F = 33.8), deepest S wave in any precordial lead plus S V4 (F = 33.7), S in V3 plus R aVL (F = 29.9), S in V4 (F = 29.79), and deepest S in precordial leads (F = 17.9). The R wave in AVL alone did not correlate with LV mass. Criteria using the R wave in lateral precordial leads did not correlate as strongly with LV mass. For women, only S in V4 significantly correlated with LV mass. Overall, the R wave voltage in limb leads (AVL I or II) did not correlate with precordial S wave amplitudes. Univariate and multivariate analysis showed that some but not all QRS voltages correlated with each other. In multivariate analysis, using only single variables and not combination of QRS variables, the only significant relationship between QRS voltage and left ventricular mass was for men the S in V3 (p = 0.04) and for women S in V4 (p = 0.016) and R in V6 (p = 0.04). The S wave in V3 and V4 correlate most strongly with LV mass while the R wave in limb leads, including AVL, do not correlate.

Digitized Electrocardiography Measurements Support the Biological Plausibility of the Pathological Significance of ST Segments in Athletes.

ST segment deviations around the isoelectric line are common findings in manifest cardiovascular disease. In athletes, ST elevation is common, while ST depression is considered rare. However, clinical studies in athletes have associated ST depression with myocardial fibrosis and fatty infiltration and ST elevation with pericarditis and myocarditis. This study aims to explore the association between resting ST segment deviations and resting heart rate, an indicator of training and autonomic tone and electrocardiography (ECG) markers of exercise training effect and cardiovascular health R and T wave amplitude. Retrospective analysis of digitized ECG data. Institutional setting. Seven thousand eight hundred thirty-six (male athletes = 4592, female athletes = 3244) healthy asymptomatic athletes (14-35 years). A series of correlations and regressions were conducted between ST depression (<0.0 µV) and ST elevation (>0.0 µV), on R and T wave amplitudes, and heart rate in leads V2, V5, and aVF. Positive correlations between ST elevation and R and T wave (S wave in V2) amplitudes and leads V5, V2, and aVF in male and female athletes (range of r = 0.1-0.54). In addition, there was a negative correlation between ST elevation and HR for male and female athletes. Finally, there was a negative correlation between ST depression and R wave and HR for male and female athletes in V5 ( P < 0.01). In athletes, ST segment elevation is correlated with R and T wave amplitudes and negatively correlated with HR. In addition, ST segment elevation is correlated with low heart rate, consistent with its higher prevalence in athletes. ST segment depression is not influenced by HR but is negatively associated with R and T wave amplitudes.

Pediatric ECG-Based Deep Learning to Predict Left Ventricular Dysfunction and Remodeling.

Artificial intelligence-enhanced ECG analysis shows promise to detect ventricular dysfunction and remodeling in adult populations. However, its application to pediatric populations remains underexplored. A convolutional neural network was trained on paired ECG-echocardiograms (≤2 days apart) from patients ≤18 years of age without major congenital heart disease to detect human expert-classified greater than mild left ventricular (LV) dysfunction, hypertrophy, and dilation (individually and as a composite outcome). Model performance was evaluated on single ECG-echocardiogram pairs per patient at Boston Children's Hospital and externally at Mount Sinai Hospital using area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC). The training cohort comprised 92 377 ECG-echocardiogram pairs (46 261 patients; median age, 8.2 years). Test groups included internal testing (12 631 patients; median age, 8.8 years; 4.6% composite outcomes), emergency department (2830 patients; median age, 7.7 years; 10.0% composite outcomes), and external validation (5088 patients; median age, 4.3 years; 6.1% composite outcomes) cohorts. Model performance was similar on internal test and emergency department cohorts, with model predictions of LV hypertrophy outperforming the pediatric cardiologist expert benchmark. Adding age and sex to the model added no benefit to model performance. When using quantitative outcome cutoffs, model performance was similar between internal testing (composite outcome: AUROC, 0.88, AUPRC, 0.43; LV dysfunction: AUROC, 0.92, AUPRC, 0.23; LV hypertrophy: AUROC, 0.88, AUPRC, 0.28; LV dilation: AUROC, 0.91, AUPRC, 0.47) and external validation (composite outcome: AUROC, 0.86, AUPRC, 0.39; LV dysfunction: AUROC, 0.94, AUPRC, 0.32; LV hypertrophy: AUROC, 0.84, AUPRC, 0.25; LV dilation: AUROC, 0.87, AUPRC, 0.33), with composite outcome negative predictive values of 99.0% and 99.2%, respectively. Saliency mapping highlighted ECG components that influenced model predictions (precordial QRS complexes for all outcomes; T waves for LV dysfunction). High-risk ECG features include lateral T-wave inversion (LV dysfunction), deep S waves in V1 and V2 and tall R waves in V6 (LV hypertrophy), and tall R waves in V4 through V6 (LV dilation). This externally validated algorithm shows promise to inexpensively screen for LV dysfunction and remodeling in children, which may facilitate improved access to care by democratizing the expertise of pediatric cardiologists.

Qualitative and Quantitative Electrocardiogram Parameters in a Large Cohort of Children with Duchenne Muscle Dystrophy in Comparison with Age-Matched Healthy Subjects: A Study from South India.

Electrocardiography (ECG) remains an excellent screening tool for cardiac assessment in Duchenne muscular dystrophy (DMD), but an accurate interpretation requires comparison with age-matched healthy controls. We examined various ECG parameters in children with DMD, in comparison with age-matched controls. Standard 12-lead ECG tracings of serial patients were screened for quality and selected. Controls were healthy, age-matched school-going children. Both quantitative and qualitative ECG parameters were analyzed. After screening, ECGs from 252 patients with DMD (8.32 ± 3.12 years, 2-21 years) and ECGs from 151 age-matched healthy controls (9.72 ± 2.23, 4-19 years) were included. A significantly higher heart rate, shorter R-R interval, and taller R wave in V1 were seen across all age group of DMD in comparison to controls, with the difference increasing with age. While QT prolongation was seen in all age groups of DMD, QTc prolongation was seen only at 10 years or more. Incomplete right bundle branch block (RBBB) and pathological Q waves in inferolateral leads were exclusive in DMD, with the latter declining with age. Evidence for left ventricular (LV) pathology, such as tall R in V5/V6, increase in SV1 + RV6 height, and QRS complex duration, were seen only in the age group of 10 years or more. Stratification based on age and comparison with age-matched healthy subjects showed that several ECG parameters were influenced by age, and it also identified age-dependent evidence for LV pathology and QTc prolongation in DMD.

Correlation between the electrocardiogram amplitude detected by an implantable cardiac monitor and the implantation depth.

Implantable cardiac monitors (ICMs) primarily use R-R intervals in subcutaneous electrocardiograms (ECGs) to detect arrhythmias. Therefore, reliable detection of R-wave amplitude by an ICM is vital. Since ICMs detect subcutaneous ECGs, the impact of the implantation depth should be assessed. This study investigated the influence of ICM depth on R-wave (ICM-R) amplitude on an ECG generated by an ICM (JOT Dx; Abbott). Overall, 58 patients who underwent ICM implantation at Kamagaya General Hospital from May 2022 to April 2023 were retrospectively reviewed. The depth-position was measured using ultrasound imaging after implantation. The depth of the ICM did not show any correlation with ICM-R amplitude (r = -.0141, p = .294). However, the distance between the ICM and the heart surface showed a significant correlation with ICM-R amplitude (r = -.581, p < .001). Body weight (r = -.0283, p = .033) and body mass index (r = -.0342, p = .009) were associated with ICM-R amplitude. S wave in the V1 -lead was also associated with ICM-R amplitude (r = .481, p < .001). After multivariate analysis, the distance between the ICM and heart surface and the S wave in V1 were independent determinants for the ICM-R amplitude. The ICM-R amplitude may be higher with the ICM implanted deeper.

Electrocardiographic left atrial abnormality and risk of heart failure

IntroductionThe association and the racial differences of the electrocardiographic markers of left atrial abnormality (ECG-LAA) with heart failure (HF) are unclear. MethodsWe examined the cross-sectional association of ECG-LAA, defined as deep terminal negativity of P wave in V1 (DTNPV1) with HF in 8460 participants (51.5% women, 60.3 ± 13.5 age and 49.8% Whites) from the US Third National Health and Nutrition Examination Survey. We excluded participants without P-wave in their ECG or with ECG findings that interfere with measurements of P-wave. DTNPV1 was automatically measured from ECGs processed at a central lab. Values of DTNPV1 ≥ 100 μV were considered abnormal. Past medical history of HF was identified through health interviews. Multivariable logistic regression analysis was used to examine the associations of DTNPV1 with HF. ResultsAbnormal DTNPV1 was detected in 3.2% (n = 271) of the participants. HF was significantly more common in individuals with abnormal, compared to those with normal, DTNPV1 (14.7% vs. 4.8%, respectively; p-value <0.001). In a model adjusted for socio-demographics and cardiovascular risk factors, ECG-LAA was associated with 98% increased odds of HF (OR (95% CI): 1.98 (1.30–3.01), p < 0.001). This association was stronger in non-White (vs. White) participants (OR (95% CI): 3.14 (1.82–5.43) vs. 1.01 (0.51–1.97), respectively; interaction p-value =0.01), but consistent in subgroups stratified by age and sex. ConclusionsECG-LAA, defined as abnormal DTNPV1, is associated with an increased risk of HF, underscoring the role of atrial disease in developing HF. Racial differences in this association exist, possibly suggesting considering ECG-LAA in personalized assessments of HF risk.