Wave In V1 Research Articles

6 Accuracy of Electrocardiography and Agreement with Echocardiography in the Diagnosis of Left Atrial Enlargement in Pediatric Patients: A Case-Control Study

Left atrial enlargement (LAE) has been established as a marker for diastolic dysfunction in left-sided cardiac disease. The gold-standard for diagnosis is the echocardiogram. In clinical practice pediatric patients who are suspicious for LAE often receive echocardiograms with concurrent electrocardiograms (ECGs) to exclude other diagnoses. Given the wider access and lower economic cost of ECGs compared to echocardiograms, ECGs have great potential to be used as a screening test to identify patients who would benefit from further investigation by echocardiography. However, the use of ECG criteria for the diagnosis of LAE has not been validated in the pediatric population. To identify the diagnostic utility of independent or combinations of ECG criteria to diagnose LAE in the pediatric population. A large retrospective case-control study (n=492) was conducted at a pediatric hospital in patients identified by echocardiography as meeting ≥1 of the following LAE criteria: 1) left atrial indexed diameter z-score ≥2.0, or 2) increased left atrial to aortic root ratio at various cutoffs (≥1.4, ≥1.6, ≥1.8). ECG criteria included: 1) a P wave ≥110 msec, 2) P mitrale ≥40 msec, and 3) a terminal negative portion of P wave in lead V1 >40 msec, 4) P/PR segment >1.4, 1.6, or 1.8 in lead II. Sensitivity, specificity, Cohen’s Kappa coefficient (κ), and receiver operating characteristic curves (ROC) were constructed to investigate the diagnostic utility of single and combination criteria. Diagnostic performance of ECG criteria had low to moderate sensitivity (20.8–55.0%) and moderate to high specificity (73.6–96.1%). The greatest agreement occurred when using two ECG criteria: P mitrale ≥40 msec and a terminal negative portion of the P wave in lead V1 >40 msec (κ = 0.221, 95% CI 0.060–0.382). ROC curve analysis further demonstrated that terminal negative P wave in V1 is the most strongly correlated with the echocardiographic criteria (AUC:0.580–0.581). The presence of positive ECG criteria indicates a probable diagnosis of LAE, however the absence of ECG criteria cannot be used to exclude this diagnosis. It should be noted that the presence of these criteria should not be used in isolation. Further research is required to determine correlation with clinical presentation and implications for clinical management.

ELECTROCARDIOGRAPHIC DEEP TERMINAL NEGATIVITY OF THE P WAVE IN V1 AND STROKE MORTALITY

Prior studies examining the link between atrial cardiopathy and stroke risk focused mainly on non-fatal stroke. We sought to examine the association between abnormal deep terminal negativity of the P wave in V1 (DTNPV1), an electrocardiographic (ECG) marker of atrial cardiopathy, with stroke

Late presentation of arrhythmogenic right ventricular cardiomyopathy in an octogenarian associated with a pathogenic variant in the plakophilin 2 gene: a case report

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease characterized by fibrofatty replacement and ventricular arrhythmias. ARVC is believed to be a disease of the young, with most cases being diagnosed before the age of 40 years. We report here a case of newly diagnosed ARVC in an octogenarian associated with a pathogenic variant in the plakophilin 2 gene (PKP2).Case presentationAn 80-year-old Japanese man was referred for sustained ventricular tachycardia. His baseline electrocardiogram showed negative T waves in V1–V4. Right ventriculography showed right ventricular aneurysm. Because this case met three major criteria, ARVC was diagnosed. He was successfully treated with radiofrequency ablation and oral amiodarone. Genetic analysis identified an insertion mutation in exon 8 of PKP2 (1725_1728dupGATG), which caused a frameshift and premature termination of translation (R577DfsX5).ConclusionsTo the best of our knowledge, this is the first report of newly diagnosed ARVC in an octogenarian associated with a loss-of-function PKP2 pathogenic variant. Although the late clinical presentation of ARVC is rare, it should be included in the differential diagnosis when treating older patients with ventricular tachyarrhythmias.

Influence of Left Bundle Branch Block on the Electrocardiographic Changes Induced by Acute Coronary Artery Occlusion of Distinct Location and Duration.

Background: Electrocardiographic (ECG) diagnosis of acute myocardial ischemia is hampered in the presence of left bundle branch block (LBBB).Objectives: We analyzed the influence of location and duration of myocardial ischemia on the ECG changes in pigs with LBBB.Methods: LBBB was acutely induced in 14 closed chest anesthetized pigs by local electrical ablation. Thereafter, episodes of 5 min catheter balloon occlusion followed by 10 min reperfusion of the left anterior descending (LAD), left circumflex (LCX), and right (RCA) coronary arteries were done sequentially in 5 pigs. Additionally, a 3-h occlusion of these arteries was performed separately in the other 9 pigs. A 15-lead ECG including leads V7 to V9 was continuously recorded.Results: Ablation induced LBBB showed QRS widening, loss of r wave in V1, and predominant R waves in V2 to V9. After 5 min of ischemia the occluded artery could be identified in all cases: the LAD by R waves and ST elevation in V1–V3; the LCX by both ST segment elevation in II, III, aVF, V7 to V9 and ST segment depression in V1 to V4; and the RCA by ST depression and new S-waves in all precordial leads. Three hours after coronary occlusion, ST segment changes declined progressively and only the LAD occlusion could be reliably recognized.Conclusion: LBBB did not mask the ECG recognition of the occluded coronary artery during the first 60 min of ischemia, but 3 h later only the LAD occlusion could be reliably identified. ST elevation in leads V7 to V9 is specific of LCX occlusion and it could be useful in the diagnosis of acute myocardial ischemia in the presence of LBBB.

Study of unexpectedly detected repolarization in a group of black athletes

IntroductionIl est considéré que la mort subite qui survient lors d'une activité sportive touche un patient ayant une cardiopathie ignorée. L'ECG du sportif de race noire a été peu étudié et des particularités liées à l'ethnie ont été évoquées. Notre travail a pour objectif d'étudier le profil épidémiologique et les particularités de la repolarisation du sportif de race noire.MéthodesUne étude descriptive a été menée durant 8 mois de mars à octobre 2014, incluant des sportifs de race noire sélectionnés parmi tous les sportifs qui étaient suivi dans le centre sectoriel de la Médecine et des Sciences de sports de Sousse. Le recueil de données a été réalisé grâce à un questionnaire medical.RésultatsTrente-cinq (35) athlètes ont été colligés, avec une prédominance masculine (94,28%), ayant un âge moyen de 24,34 ans. Quatre athlètes avaient une hypertrophie ventriculaire gauche à l'échographie cardiaque. Il y'avait 8 athlètes avec un BAV de 1er degré et 8 athlètes avaient un HVG électrique. Les modifications du segment ST étaient plus marquées au niveau des dérivations précordiales. Cinq athlètes (14,2%) avaient des ondes T négatives en V2 et V3, et il s'agissait des mêmes athlètes qui avaient le sus décalage du segment ST dans ces mêmes dérivations. Un aspect de repolarisation précoce a été constaté chez 3 athlètes. Tous ces cas étaient type notch.ConclusionLes sportifs de race noire semblent avoir des modifications électriques assez spécifiques dont il importe de connaitre. Toutefois, notre échantillon n'est pas suffisamment important pour affirmer ces résultats. Une étude comparative avec des sportifs de race blanche serait très intéressante.

Atypical ischemic repolarization in right bundle branch block

A 70-year-old male presented to emergency room 16 h after the onset of acute chest pain. Initial ECG showed sinus rhythm with a wide QRS and right bundle branch block (RBBB) with concordant and symmetric T waves in V1–V2. A plausible explanation for the atypical positive T waves in leads V1–V2 in conjunction with RBBB could be non-reperfused lateral MI (LMI) as a “mirror-image” of inverted T waves in the posterior leads V7–V9. Coronary angiography showed total thrombotic occlusion TIMI thrombus grade 5 of the circumflex artery. One ECG expression of circumflex artery occlusion is isolated LMI.

PO448 Evaluation of Mortality Trends From Cardiac Arrest In Brazil and the Southeast Region, and the Importance of First Aid to Victims

Each encounter of asymptomatic individuals with the healthcare system presents an opportunity for improvement of cardiovascular disease (CVD) awareness and sudden cardiac death (SCD) risk assessment. ECG sign deep terminal negativity of the P wave in V1 (DTNPV1) was shown to be associated with an increased risk of SCD in the general population.To evaluate association of DTNPV1 with all-cause mortality and newly diagnosed atrial fibrillation (AFib) in the large tertiary healthcare system patient population.Retrospective double cohort study compared two levels of exposure (automatically measured amplitude of P-prime (Pp) in V1): DTNPV1 (Pp from − 100 μV to − 200 μV) and ZeroPpV1 (Pp = 0). An entire healthcare system (2010–2014) ECG database was screened. Medical records of children and patients with previously diagnosed AFib/atrial flutter (AFl), implanted pacemaker or cardioverter–defibrillator were excluded. DTNPV1 (n = 3,413) and ZeroPpV1 (n = 3,405) cohorts were matched by age and sex. Primary outcome was all-cause mortality. Secondary outcomes were newly diagnosed AFib/AFl. Median follow-up was 2.5 y.DTNPV1 was associated with all-cause mortality (HR 1.95(1.64–2.31); P < 0.0001) and newly diagnosed AFib (HR 1.29(1.04–1.59); P = 0.021) after adjustment for CVD, comorbidities, other ECG parameters, medications, and index ECG referral. Index ECG referral by a cardiologist was independently associated with 34% relative risk reduction of mortality (HR 0.66(0.52–0.84); P = 0.001), as compared to ECG referral by a non-cardiologist.DTNPV1 is independently associated with twice higher risk of all-cause death, as compared to patients without P prime in V1. Life-saving effect of the index ECG referral by a cardiologist requires further study.

A17693 Investigation of the Peguero-Lo Presti Criteria to Improve the Sensitivity of the Electrocardiogram to Diagnose Left Ventricular Hypertrophy in Patients with Type 2 Diabetes

Objectives: In 2107, Peguero et al described a new electrocardiographic (ECG) criteria (the SD + SV4 -Peguero-Lo Presti [PLP]) with improved sensitivity and accuracy to diagnose left ventricular hypertrophy (LVH). We tested its performance to detect echocardiographic-LVH (ECHO-LVH) in patients at increased risk of cardiovascular (CV) disease due to type 2 diabetes.<ST>Methods:</ST> We prospectively recruited 106 patients with type 2 diabetes who were asymptomatic of cardiac disease for ECG and echocardiogram. After excluding 18 with RBBB/LBBB or paced rhythm, we analysed data from 88 patients. ECHO-LVH was defined according to ASE guidelines and compared to five ECG-LVH criteria (PLP, Sokolow-Lyon [SL], Cornell, RaVL, RLI). The PLP criteria was met when the sum of the deepest S wave in any lead (SD) and S wave in V4 was ≥ 2.3 mV (female) or ≥ 2.8 mV (male). Analyses were reviewed by 2 investigators blinded to other imaging results.<ST>Results:</ST> Mean age was 68 ± 10 years, 64% were male and 84% had hypertension. ECHO-LVH was present in 26 patients (29%). The PLP criteria had nominally the best sensitivity to detect LVH (15.3%; 95% confidence interval [CI]: 6% to 33%), followed by Cornell criteria (7.7%; CI: 2% to 24%), RaVL (7.7%; CI: 2% to 24%) and SL (3.8 %; CI: 1% to 18%) (all p < 0.001, McNemar test). Specificities of all criteria were ≥ 93%.<ST>Conclusion:</ST> Nearly 30% of patients with type 2 diabetes had occult LVH on echocardiography. The Peguero-Lo Presti criteria was a more sensitive method to ECHO-LVH compared to existing ECG criteria but only detected 4 of the ECHO-LVH cases. As LVH is associated with adverse CV outcomes, these results suggest an echocardiogram should be the investigation of first choice to assess subclinical cardiac disease in patients with diabetes.

Extrasístoles ventriculares: relación deflexión intrinsecoide / QRS para discriminar el origen

Introducción: las taquicardias ventriculares (TV) y complejos ventriculares prematuros (CVP) de los tractos de salida (TS) son arritmias ventriculares más frecuentes que se producen en el corazón estructuralmente sano. El manejo intervencionista con ablación es el tratamiento que en casos seleccionados ha demostrado tener mayor efectividad terapéutica; para optimizar el lugar de ablación sobre el foco de origen se han conformado ayudas complementarias a los estudios de extensión. Objetivo: proponer una herramienta para discriminar tempranamente el origen de las extrasístoles ventriculares provenientes de los tractos de salida a partir del cálculo del valor de la relación deflexión intrinsecoide/QRS medida en extrasístoles ventriculares en V6. Materiales y métodos: se realizó un estudio de corte transversal, en pacientes con diagnóstico de CVP llevados a estudio electrofisiológico más ablación exitosa. Se midió la deflexión intrinsecoide y se relacionó con el tiempo total del QRS en V6. Resultados: a partir de los análisis de los puntos del corte se estableció un valor de la relación deflexión intrisecoide/qrs menor o igual a 0.67 para el ventrículo derecho y mayor o igual a o.68 para el ventrículo izquierdo. El análisis de los datos registró una correcta clasificación de los pacientes en el 80% de los casos. Conclusiones: este estudio propone una herramienta corta y sencilla de aplicar, que intenta predecir el origen de estas arritmias a partir de unas mediciones realizadas en un electrocardiograma en que se muestre dicha extrasístole ventricular en V6, en donde es obtener posible origen del foco arritmogénico antes del procedimiento intervencionista.

Association between serum cotinine levels and electrocardiographic left atrial abnormality.

Although the harmful effect of tobacco exposure on cardiovascular disease (CVD) and its risk factors are well established, the constituents of cigarette-smoke and the pathophysiological mechanism involved are unknown. Recently, deep terminal negativity of P wave in V1 (DTNPV1) has emerged as a marker of left atrial abnormality that predicts atrial fibrillation, stroke, and death due to all-cause or CVD. Therefore, we examined the association between serum cotinine levels with abnormal DTNPV1 using the Third National Health and Nutrition Examination Survey. This analysis included 4,507 participants (mean age 58±13years, 53% women, 49% non-Hispanic white) of NHANES III, without history of CVD or major electrocardiographic abnormalities and not on heart rate modifying medications. Multivariable logistic regression analysis was used to examine the association between serum cotinine and abnormal DTNPV1-defined from automatically processed electrocardiograms as values of the amplitude of the terminal negative phase of P wave in lead V1 exceeding 100μV. Abnormal DTNPV1 was detected in 2.3% (n=105) of the participants. In a model adjusted for demographics and CVD risk factors, each 10ng/ml serum cotinine was associated with 2% increased odds of abnormal DTNPV1 (odds ratio 1.02, 95% confidence interval 1.01-1.03, p-value<0.001). This association was consistent in subgroups stratified by age, sex, race, smoking status, hypertension, diabetes, dyslipidemia, and chronic obstructive pulmonary disease. Elevated serum cotinine levels are associated with an abnormal DTNPV1. This suggests that nicotine exposure can lead to left atrial abnormalities, a possible mechanism for increased risk of CVD.

Severe suicidal self-poisoning with massive dose of potassium ferricyanide(III): hyperkalemia but not free cyanide may cause death

Potassium ferricyanide(III), K3[Fe(CN)6], has a widespread use in blueprint drawing, photography, chemical industry, and metallurgy. In mice, the oral lethal dose 50 (LD50) is 1600 mg kg−1. We report the case of a suicide attempt in a 37-year-old male by intentional ingestion of 80 g of potassium ferricyanide(III) dissolved in water. The estimated ingested dose was 770 mg kg−1. The patient reported vertigo as the first sign of poisoning and six episodes of diarrhea with dark-colored stool 2 h after ingestion. The patient was transported by ambulance to the intensive care unit 8 h after ingestion. He was conscious and spontaneously ventilating, with a Glasgow Coma Scale (GCS) score of 15. On ECG performed at admission, tall “tented” T waves in V3–V6 and progressive flattering of P waves were registered. Serum concentrations of potassium of 7.2 mmol dm−3, urea of 7.1 mmol dm−3, and creatinine of 162 µmol dm−3 indicated development of acute renal failure. Despite the administration of intravenous insulin and 10% glucose infusion during the first hours after admission, there was a further elevation of serum potassium to 7.4 mmol dm−3 suggesting acute renal failure. For this reason, intermittent hemodialysis was performed [duration 200 min, blood flow rate 147 cm3 min−1, online clearance monitoring (OCM) clearance rate 100 cm3 min−1, and substitution fluid volume 5.8 dm3]. The condition of the patient stabilized and he was discharged from hospital on the fourth day after admission. This case report demonstrates the risks of life-threatening hyperkalemia and acute renal failure as complications of massive ingestion of potassium ferricyanide(III).

Improvement in the electrocardiograms associated with right ventricular hypertrophy after balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension

BackgroundBalloon pulmonary angioplasty (BPA) is a treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods and resultsIn 60 patients with CTEPH, we examined the hemodynamic data before and after BPA. In addition, the sequential ECG findings for right ventricular hypertrophy (RVH) were assessed. The mean pulmonary arterial pressure (mPAP) decreased from 38 ± 11 to 20 ± 4 mm Hg (p < 0.05). The ROC analysis showed that the S waves in V5, R waves in V1 + S waves in V5, S waves in I, and QRS axis were significant predictors of an mPAP ≧ 30 mm Hg (AUC > 0.75, p < 0.01). The predictive values for the mPAP before the BPA were the S and R waves in lead V6, and P waves in lead II (33.417 + 0.078 × P in II − 0.10 × R in V6 + 0.012 × S in V6). The change in the mPAP (ΔmPAP) correlated with the change in the amplitudes of the ECGs: ΔS wave in lead I (R = 0.544, p < 0.001), ΔR in V1 + S in V5 (R = 0.476, p < 0.001), and ΔP wave in II (R = 0.511, p < 0.001). At 6 months of follow-up, the improvement in an R in V1 + S in V5 of ≧10 mm implied a better functional status. ConclusionBPA therapy reduced the pulmonary arterial pressure in patients with CTEPH and was associated with an improvement in the ECG findings related to RVH.

Distinct ECG Phenotypes Identified in Hypertrophic Cardiomyopathy Using Machine Learning Associate With Arrhythmic Risk Markers.

Aims: Ventricular arrhythmia triggers sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM), yet electrophysiological biomarkers are not used for risk stratification. Our aim was to identify distinct HCM phenotypes based on ECG computational analysis, and characterize differences in clinical risk factors and anatomical differences using cardiac magnetic resonance (CMR) imaging.Methods: High-fidelity 12-lead Holter ECGs from 85 HCM patients and 38 healthy volunteers were analyzed using mathematical modeling and computational clustering to identify phenotypic subgroups. Clinical features and the extent and distribution of hypertrophy assessed by CMR were evaluated in the subgroups.Results: QRS morphology alone was crucial to identify three HCM phenotypes with very distinct QRS patterns. Group 1 (n = 44) showed normal QRS morphology, Group 2 (n = 19) showed short R and deep S waves in V4, and Group 3 (n = 22) exhibited short R and long S waves in V4-6, and left QRS axis deviation. However, no differences in arrhythmic risk or distribution of hypertrophy were observed between these groups. Including T wave biomarkers in the clustering, four HCM phenotypes were identified: Group 1A (n = 20), with primary repolarization abnormalities showing normal QRS yet inverted T waves, Group 1B (n = 24), with normal QRS morphology and upright T waves, and Group 2 and Group 3 remaining as before, with upright T waves. Group 1A patients, with normal QRS and inverted T wave, showed increased HCM Risk-SCD scores (1A: 4.0%, 1B: 1.8%, 2: 2.1%, 3: 2.5%, p = 0.0001), and a predominance of coexisting septal and apical hypertrophy (p < 0.0001). HCM patients in Groups 2 and 3 exhibited predominantly septal hypertrophy (85 and 90%, respectively).Conclusion: HCM patients were classified in four subgroups with distinct ECG features. Patients with primary T wave inversion not secondary to QRS abnormalities had increased HCM Risk-SCD scores and coexisting septal and apical hypertrophy, suggesting that primary T wave inversion may increase SCD risk in HCM, rather than T wave inversion secondary to depolarization abnormalities. Computational ECG phenotyping provides insight into the underlying processes captured by the ECG and has the potential to be a novel and independent factor for risk stratification.

Electrocardiographic Parameters as Predictors of Response to Cardiac Resynchronization Therapy.

INTRODUCTION:Although strict selection criteria are used to select patients for cardiac resynchronisation therapy, up to 30% of patients do not have a positive clinical response.PATIENTS:A total of 102 consecutive patients who had biventricular pacemaker/defibrillator (CRT-P or CRT-D) implanted were enrolled in this prospective observational study.RESULTS:During the average follow-up period of 24.3 months 5 patients died and 17 (16.7%) patients were hospitalised with the symptoms of heart failure; 75 (73.5%) patients were responders based on the previously defined criteria. Responders in the group of LBBB patients kept the significant difference in a computed variable (S1 + R6) - (S6 + R1) and R6/S6 ratio. Responders in non-LBBB patients kept the significant difference only in the height of R waves in V6. The R6/S6 ratio tended to be higher, but it did not reach a statistical significance.CONCLUSION:None of the tested ECG parameters stands out as an independent predictor of response to cardiac resynchronisation therapy, but some of them were different in responder-compared to the non-responder group. The amplitude of R wave in V6, higher R/S ratio in V6 and higher computed variable (S1 + R6) - (S6 + R1) may predict the likelihood of response to CRT therapy in both LBBB-patients and non-LBBB patients.

Oštećenje miokarda uzrokovano kombinacijom emocionalnog stresa i trovanja ugljen monoksidom - prikaz slučaja

Introduction: Carbon monoxide (CO) is a leading cause of poisoning worldwide.Central nervous systems and the heart have the highest demand for oxygen and may be severely injured in CO poisoning. Case report: A patient was referred to the emergency department after exposure to CO and strong emotional stress. On admission she was comatose with elevated lactate 14,62, metHgb 0,3% and carboxyhemoglobin 12,9%. Electrocardiogram showed sinus rhythm, 100 beats/min, poor R wave progression with inverted T waves in V1-V3 leads, biphasic T waves in V5 and V6. Transthoracic echocardioography showed left ventricle with akinetic apex and all apical segments of the left ventricle with reduced systolic function. Cardiac troponin was significantly elevated; coronary angiography showed normal coronary arteries without culprit lesion. Takotsubo syndrome was diagnosed. She was treated with high flow oxygen on mechanical ventilation, antiplatelet, angi-otenzinconvertase inhibitors, beta blockers and statin therapy with complete recovery. After one month ehocardiography showed left ventricle normal in size and function. Conclusion: CO poisoning hasn't yet been described as a trigger for Takotsubo syndrome. We propose that two risk factors CO poisoning and stress by may have initiated a catecholamine surge and caused the development of this specific condition.

Upright T Wave in Lead V1 as an Important Predictor of Significant Coronary Artery Disease in Patients with Chest Pain

Background: Cardiovascular disease is a worldwide great burden on the health care syste early diagnosis and treatment of CAD can reduce the mortality and morbidity. We aimed to determine the association between upright T wave in lead V1 and coronary artery disease (CAD) in patients who presented with chest pain or positive non-invasive tests in emergency department. Methods: In this retrospective cross sectional design we reviewed the clinical and coronary angiography data of patients who had normal ECG. Presence of coronary artery disease was compared between patients with and without upright T waves in V1. Results: Data of 100 patients with upright T wave more than 1.5 mm in V1 was compared with 100 patients with completely normal ECG. Male patients with coronary artery disease (CAD) were dominant in upright T wave group. However, other traditional cardiovascular risk factors were not statistically different between groups. Based on the multivariate logistic regression model and after adjustment for confounding factors (i.e. gender, dyslipidemia and smoking), presence of upright T wave in the V1 and male gender were still associated with greater risk of coronary artery disease, Odds ratio 4.6 CI 95% (3.1 - 6.3) and 3.4 CI 95% (2.2 - 4.8), respectively. Conclusions: In patients with chest pain and unremarkable ECG, presence of upright T wave in lead V1, is an early diagnostic tool for CAD. Male patients with chest pain and upright T wave in lead V1 probably have significant CAD.

Electrocardiographic patterns in biventricular pacing delivered by second-generation cardiac resynchronization devices

BackgroundWith increasing use of cardiac resynchronization therapy (CRT), treating physicians should be familiar with different electrocardiographic (ECG) patterns of left ventricular (LV) lead and biventricular (BiV) pacing. However, there are a few publications on ECG patterns during BiV pacing. PurposeThis study was sought to determine different ECG patterns in patients with BiV pacing. MethodsTwelve-lead ECGs during BiV pacing (right ventricular leads at apex and LV leads in one of the lateral coronary veins) were analyzed in 181 consecutive patients (121 male; mean age, 62.0 ± 13.5 years) with advanced heart failure and baseline left bundle branch block pattern after at least 6-month of uncomplicated CRT. ResultsDuring BiV pacing, 65% of the patients showed a dominant R wave in V1. There was a right axis deviation in 57% in frontal plane. However, a left superior axis emerged in 34% and normal frontal plane axis in 9%. Sequential BiV pacing (73% vs. 58%, P = 0.04) and pacing from posterolateral coronary vein (80% vs. 60%, p = 0.045) were more likely to present with a dominant R wave in V1. In sequential pacing, AV interval was significantly longer in patients with negative complex in V1 than in those with positive complex (124 ± 21 vs. 116 ± 8.0, p = 0.005). A Q/q wave was detected in 85% of patients in lead I and 78% in lead aVL. ConclusionsBiV pacing from lateral coronary venous branches and right ventricular apex characteristically presented with dominant R wave in V1, Q/q wave in leads I and aVL, and right or left superior axis. However, a negative complex in V1, QRS axis in other quadrants, and lack of Q/q wave in leads I and aVL did not necessarily indicate a problem.

Time-compressed preplay of anticipated events in human primary visual cortex

Perception is guided by the anticipation of future events. It has been hypothesized that this process may be implemented by pattern completion in early visual cortex, in which a stimulus sequence is recreated after only a subset of the visual input is provided. Here we test this hypothesis using ultra-fast functional magnetic resonance imaging to measure BOLD activity at precisely defined receptive field locations in visual cortex (V1) of human volunteers. We find that after familiarizing subjects with a spatial sequence, flashing only the starting point of the sequence triggers an activity wave in V1 that resembles the full stimulus sequence. This preplay activity is temporally compressed compared to the actual stimulus sequence and remains present even when attention is diverted from the stimulus sequence. Preplay might therefore constitute an automatic prediction mechanism for temporal sequences in V1.

Ventricular tachycardia score – A novel method for wide QRS complex tachycardia differentiation – Explained

Philosophy, merits and limitations of a novel method for wide QRS complex tachycardia differentiation, based on a scoring system and called the ventricular tachycardia (VT) score, were explained. The following criteria were assigned one point: initial dominant R wave in V1; initial r>40 ms in V1 or V2; notched S in V1; initial R wave in aVR; lead II RWPT≥50 ms; and absence of an RS in leads V1–V6. Atrioventricular dissociation (including fusion/capture beats and partial dissociation) was assigned two points. We recommend ≥3 VT score points for a firm diagnosis of VT. A cut-off ≥1 point can be used for diagnosis of VT when highest overall accuracy rather than error-free diagnosis is desired. However, in case of VT score of 0–2 (i.e., not fully diagnostic ECG), we recommend using other options (electrophysiological study, clinical data, previous and following ECGs, etc.) for confirming the diagnosis.

Platitudes and Attitudes.

Platitudes and Attitudes.