Mm In Leads V1 Research Articles

Interatrial block, P terminal force or fragmented QRS do not predict new-onset atrial fibrillation in patients with severe chronic kidney disease

BackgroundThe prevalence of left atrial enlargement (LAE) and fragmented QRS (fQRS) diagnosed using ECG criteria in patients with severe chronic kidney disease (CKD) is unknown. Furthermore, there is limited data on predicting new-onset atrial fibrillation (AF) with LAE or fQRS in this patient group.MethodsWe enrolled 165 consecutive non-dialysis patients with CKD stage 4–5 without prior AF diagnosis between 2013 and 2017 in a prospective follow-up cohort study. LAE was defined as total P-wave duration ≥120 ms in lead II ± > 1 biphasic P-waves in leads II, III or aVF; or duration of terminal negative portion of P-wave > 40 ms or depth of terminal negative portion of P-wave > 1 mm in lead V1 from a baseline ECG, respectively. fQRS was defined as the presence of a notched R or S wave or the presence of ≥1 additional R waves (R’) or; in the presence of a wide QRS complex (> 120 ms), > 2 notches in R or S waves in two contiguous leads corresponding to a myocardial region, respectively.ResultsMean age of the patients was 59 (SD 14) years, 56/165 (33.9%) were female and the mean estimated glomerular filtration rate was 12.8 ml/min/1.73m2. Altogether 29/165 (17.6%) patients were observed with new-onset AF within median follow-up of 3 [IQR 3, range 2–6] years. At baseline, 137/165 (83.0%) and 144/165 (87.3%) patients were observed with LAE and fQRS, respectively. Furthermore, LAE and fQRS co-existed in 121/165 (73.3%) patients. Neither findings were associated with the risk of new-onset AF within follow-up.ConclusionThe prevalence of LAE and fQRS at baseline in this study on CKD stage 4–5 patients not on dialysis was very high. However, LAE or fQRS failed to predict occurrence of new-onset AF in these patients.

In inferior myocardial infarction, neither ST elevation in lead V1 nor ST depression in lead I are reliable findings for the diagnosis of right ventricular infarction

ObjectiveIn the presence of inferior myocardial infarction (MI), ST depression (STD) in lead I has been claimed to be accurate for diagnosis of right ventricular (RV) MI. We sought to evaluate this claim and also whether ST Elevation (STE) in lead V1 would be helpful, with or without STD in V2. MethodsRetrospective study of consecutive inferior STEMI, comparing ECGs of patients with, to those without, RVMI, as determined by angiographic coronary occlusion proximal to the RV marginal branch. STE and STD were measured at the J-point, relative to the PQ junction. The primary outcomes were sensitivity/specificity of 1) STD in lead I ≥ 0.5 mm and 2) STE in lead V1 ≥ 0.5 mm, stratified by presence or absence of posterior (inferobasal) MI, as determined by ≥0.5 mm STD in lead V2, for differentiating RVMI from non-RVMI. ResultsOf 149 patients with inferior STEMI, 43 (29%) had RVMI and 106 (71%) did not. There was no difference in the presence or absence of at least 0.5 mm STD in Lead I between patients with (37/43, 86%) vs. without RVMI (85/106, 80%, p = 0.56). In those with, vs. without, RVMI, (15/43, 35%) had STE in V1, versus (17/106, 16%) (p = 0.015). Specificity of STE in V1 for RVMI was 84%; sensitivity was 35%. Sensitivity was higher without (69%), than with (35%), STD in V2. ConclusionAmong inferior STEMI, the presence of any ST depression in lead I does not help to diagnose RVMI. ST elevation ≥0.5 mm in lead V1 is specific for RVMI, and moderately sensitive only if concomitant STD ≥ 0.5 mm in V2 is not present. Although STE in V1 is quite specific, overall the diagnostic characteristics of the standard 12‑lead ECG are inadequate to definitively diagnose, or exclude, RVMI, as defined angiographically.

Correlation of right atrial enlargement on ECG to right atrial volume by echocardiography in patients with pulmonary hypertension

Previous attempts to validate ECG criteria for right atrial (RA) enlargement (RAE) have been limited by sample sizes and lack of accepted standards for measuring RA size. New guidelines have recommended that RA volume (RAV) be used to determine RA size. Since these guidelines were released, no studies have been published that correlate RAE by ECG to RAV using the new standards. We aimed to validate previously proposed ECG criteria for RAE, commonly called P pulmonale, and to establish whether a correlation exists between P wave amplitudes and RAV as determined by echocardiogram in patients from the pulmonary hypertension (PHT) clinic. We identified patients from the PHT clinic that had an echocardiogram and ECG done at most 30days apart. We defined increased P wave amplitude as ≥2mm in lead II and ≥1mm in lead V1. The RA was determined to be enlarged if the RAV index (RAVI) was ≥39mL/m2 for men and ≥33mL/m2 for women. Patients were stratified into four groups: those with P II≥2mm, those with P V1≥1mm, those that met both criteria, and those that met neither. Right atrial volumes were then compared. Sixty-three patients were included in the study (7 men, 56 women). Three men and 36 women had an ECG that met criteria for P pulmonale. Five men and 28 women had an enlarged RA on echocardiogram. Sixty-nine percent of ECGs that met criteria for RAE were associated with increased RAV by echocardiogram. The specificity of each of the ECG criteria for P pulmonale at detecting RAE was 100% for men. The criterion with the highest specificity among women was P II≥2mm AND P V1≥1mm (94%). The least specific criterion for women was P II≥2mm (70%). The sensitivity of each criterion was much lower. The most sensitive criteria for men and women were P V1≥1mm (66.6%) and P II≥2mm (48%), respectively. The correlation of P wave amplitude in leads II and V1 and RAVI was not statistically significant for any of the ECG criteria for P pulmonale. In patients from the PHT clinic, the specificity of P pulmonale for detecting RAE is high, but the sensitivity is relatively low. These results suggest that in PHT, P pulmonale can be used to confirm that the RA is enlarged, but it is not a reliable test for diagnosing RAE.

ST-segment elevation in lead aVR in the setting of acute coronary syndrome

Objectives The purpose of our study was to assess the value of aVR ST-segment elevation (STE) during acute non ST-segment elevation myocardial infarction (NSTEMI) or unstable angina. Background STE in lead aVR has been associated with severe coronary lesions in patients with acute coronary syndromes. However, there are conflicting data regarding the prognostic significance of this finding.Methods We evaluated the initial electrocardiogram (ECG) in 129 patients admitted to our hospital with acute NSTEMI or unstable angina without STE in leads other than aVR or V1. STE in aVR lead was measured and echocardiography and coronary angiography were performed within 48-72 hours after hospitalization. Results Overall, 40.3% (52 patients) had more than 0.05 mv STE in lead aVR. These patients had an increased prevalence of ST ≥ 1 mm in lead V1, a more frequent and extensive ST-segment depression (STD) in other leads, a higher prevalence of anterior and lateral STD and a lower frequency of isolated negative T waves. It was also strongly associated with cardiac enzyme rising and a trend toward higher 3-month mortality. Furthermore, patients with STE in lead aVR were more likely to have three-vessel or multivessel disease, higher Gensini score of the coronary arteries, lower left ventricular ejection fraction (LVEF) and higher incidence of mitral regurgitation (MR).Conclusions Our study showed that among ECG markers, the sole criterion STE in lead aVR was independently associated with atherosclerosis severity and decreased LVEF. Also, it was significantly associated with the presence of MR.

Management of an asymptomatic patient with dynamically changing J wave from inferior early repolarization to Brugada pattern

Case report A 33-year-old man was referred to our institution for investigation of type 1 Brugada syndrome (BS) fortuitously discovered on a routine electrocardiogram (ECG) recorded at an occupational medicine clinic. The patient had no family history of structural heart disease or sudden death and no personal medical history. He was completely asymptomatic at the time of the initial examination. The 12-lead ECG at admission (Figure 1) reveals a normal sinus rhythm with a significant ST-segment elevation of more than 2 mm in leads V1 and V2 diagnostic of a type 1 BS. We also noted the presence of a significant slurred J wave in the inferior leads diagnostic of early repolarization (ER) pattern. At baseline, the maximal amplitude of the J wave was 5 mm (0.5 mV) in lead V1 and 4 mm (0.4 mV) in lead III. As we performed routine Valsava maneuvers, we observed significant change in the J wave in amplitude and distribution (Figure 2). Immediately after the end of maneuvers the J wave became maximal in the inferior leads and extended all the way to the T wave (amplitude of 5 mm in lead III) while J wave decreased in the anterior leads (disappeared in lead V1 and maximal amplitude of 4 mm in lead V2). Rapidly after the end of the Valsalva maneuver, a gradual transition of the ECG back to its initial form was subsequently observed. The same phenomenon was obtained reproducibly with Valsalva maneuvers. Multiple ECG recordings and continuous heart rhythm telemetry also demonstrated extreme fluctuation of the J wave in amplitude and distribution from predominant Brugada pattern to predominant ER pattern to normal ECG (Figure 3). During hospitalization, the patient underwent an extensive cardiac

Is it possible to differentiate between Takotsubo cardiomyopathy and acute anterior ST-elevation myocardial infarction?

IntroductionSeveral studies have investigated the ability of the twelve-lead electrocardiogram (ECG) to reliably distinguish Takotsubo cardiomyopathy (TC) from an acute anterior ST-segment elevation myocardial infarction (STEMI). In these studies, only ECG changes were required – ST-segment deviation and/or T-wave inversion – in TC whereas in acute anterior STEMI, ECGs had to meet STEMI criteria. In the majority of these studies, patients of both genders were used even though TC predominantly occurs in women. The aim of this study is to see whether TC can be distinguished from acute anterior STEMI in a predominantly female study population where all patients meet STEMI-criteria. MethodsRetrospective analysis of the ST-segment changes was done on the triage ECGs of 37 patients with TC (34 female) and was compared to the triage ECGs of 103 female patients with acute anterior STEMI. The latter group was divided into the following subgroups: 46 patients with proximal, 47 with mid and 10 with distal LAD occlusion. Three ST-segment based ECG features were investigated: (1) Existing criterion for differentiating anterior STEMI from TC: ST-segment depression >0.5mm in lead aVR+ST-segment elevation ≤1mm in lead V1, (2) frontal plane ST-vector and (3) mean amplitude of ST-segment deviation in each lead. ResultsThe existing ECG criterion was less accurate (76%) than in the original study (95%), with a large difference in sensitivity (26% vs. 91%). Only a frontal plane ST-vector of 60° could significantly distinguish TC from all acute anterior STEMI subgroups (p<0.01) with an overall diagnostic accuracy of 81%. The mean amplitude in inferior leads II and aVF was significantly higher for patients with TC compared to all patients with acute anterior STEMI (p<0.01 and p<0.05 respectively) and the mean amplitude in the precordial leads V1 and V2 was significantly lower compared to proximal and mid LAD occlusion (p<0.01). ConclusionsGiven the consequences of missing the diagnosis of an acute anterior STEMI the diagnostic accuracy of the ECG criteria investigated in this retrospective study were insufficient to reliably distinguish patients with TC from patients with an acute anterior STEMI. To definitely exclude the diagnosis of an acute anterior STEMI coronary angiography, which remains the gold standard, will need to be performed.

Greater response to cardiac resynchronization therapy in patients with true complete left bundle branch block: a PREDICT substudy

Cardiac resynchronization therapy (CRT) benefits patients with heart failure and a wide QRS complex. Still, one-third derive no clinical benefit and a majority of patients demonstrate no objective improvement of left ventricular (LV) function. Left bundle branch block (LBBB) is a strong predictor of response to CRT. We evaluated whether absence of electrocardiogram (ECG) markers of residual left bundle (LB) conduction in guideline-defined LBBB predicted a greater response to CRT. An r wave ≥1 mm in lead V1 (r-V1) and/or a q wave ≥1 mm in lead aVL (q-aVL) was used to identify patients with residual LB conduction. Forty patients with a wide QRS were prospectively enrolled and subdivided into three groups: complete LBBB (cLBBB), LBBB without r-V1 or q-aVL (n = 12); LBBB with residual LB conduction (rLBBB), LBBB with r-V1 and/or q-aVL (n = 15); and non-specific intraventricular conduction delay (IVCD), (n = 13). Following CRT: mean change in left ventricular ejection fraction was 11.9 ± 11.9% in cLBBB, 3.8 ± 5.4% in rLBBB (P= 0.045), and 2.5 ± 4.4% in IVCD (P= 0.02 cLBBB vs. IVCD); mean reduction in left ventricular end-systolic volume was 26.4 ± 39.2% in cLBBB, 14.3 ± 22.9% in rLBBB (P= 0.35), and 5.6 ± 17.3% in IVCD (P= 0.11 cLBBB vs. IVCD); mean change in native QRS duration was -8.0 ± 11.0 ms in cLBBB, -0.8 ± 8.24 ms in rLBBB (P= 0.07), and 0.15 ± 8.0 ms in IVCD (P= 0.048 cLBBB vs. IVCD). In patients with guideline-defined LBBB, the absence of ECG markers of residual LB conduction was predictive of a greater improvement in LV function with CRT.

The Surface Electrocardiogram Predicts Risk of Heart Block During Right Heart Catheterization in Patients With Preexisting Left Bundle Branch Block: Implications for the Definition of Complete Left Bundle Branch Block

Patients with left bundle branch block (LBBB) undergoing right heart catheterization can develop complete heart block (CHB) or right bundle branch block (RBBB) in response to right bundle branch (RBB) trauma. We hypothesized that LBBB patients with an initial r wave (>or=1 mm) in lead V1 have intact left to right ventricular septal (VS) activation suggesting persistent conduction over the left bundle branch. Trauma to the RBB should result in RBBB pattern rather than CHB in such patients. Between January 2002 and February 2007, we prospectively evaluated 27 consecutive patients with LBBB developing either CHB or RBBB during right heart catheterization. The prevalence of an r wave >or=1 mm in lead V1 was determined using 118 serial LBBB electrocardiographs (ECGs) from our hospital database. Catheter trauma to the RBB resulted in CHB in 18 patients and RBBB in 9 patients. All 6 patients with >or=1 mm r wave in V1 developed RBBB. Among these 6 patients q wave in lead I, V5, or V6 were present in 3. Four patients (3 in CHB group and 1 in RBBB group) developed spontaneous CHB during a median follow-up of 61 months. V1 q wave >or=1 mm was present in 28% of hospitalized complete LBBB patients. An initial r wave of >or=1 mm in lead V1 suggests intact left to right VS activation and identifies LBBB patients at low risk of CHB during right heart catheterization. These preliminary findings indicate that an initial r wave of >or=1 mm in lead V1, present in approximately 28% of ECGs with classically defined LBBB, may constitute a new exclusion criterion when defining complete LBBB.

Utilidad del electrocardiograma para predecir el lugar de la oclusión en el infarto agudo de miocardio anterior con enfermedad aislada de la arteria descendente anterior

In acute anterior myocardial infarction (AMI), the site of occlusion in the left anterior descending coronary artery (LAD) is related to the extension of myocardial necrosis and the prognosis. The aim of this study was to assess the value of the electrocardiogram (ECG) as a predictor of the LAD occlusion site in patients with anterior AMI. Forty-five consecutive patients with a first anterior AMI and isolated disease of the LAD were included. We evaluated retrospectively the ECG with the most pronounced ST-segment changes before fibrinolysis and correlated the findings with the site of LAD occlusion in angiography before hospital discharge in relation to the first dominant septal and first diagonal branch: first septal affected (S), first diagonal affected (D), both affected (S + D), or neither affected were considered. ST depression in leads II, III, or aVF strongly predicted proximal LAD occlusion in S + D, S, and D (p = 0,003, p = 0,04, and p = 0,02, respectively). ST elevation in leads II, III, or aVF was observed only in the presence of wrap-around LAD and was related with occlusion distal to the first diagonal branch. ST elevation > or = 3 mm in lead V1 was a specific predictor of occlusion proximal to first septal (S, p = 0,01). ST elevation in aVR was associated with proximal LAD occlusion in S + D and S (p = 0,03 and p = 0,03, respectively) and absence of coronary collateral circulation. In anterior AMI and isolated LAD disease, the ECG can be useful in predicting the LAD occlusion site in relation to its major side branches.

Value of electrocardiogram in diagnosing right ventricular involvement in patients with an acute inferior wall myocardial infarction.

To study the value of the electrocardiogram in diagnosing right ventricular involvement in acute inferior wall myocardial infarction, the electrocardiographic findings were analysed in 67 patients who had had scintigraphy to pin-point the infarct. All 67 patients were consecutively admitted because of an acute inferior wall infarction. A 12 lead electrocardiogram with four additional right precordial leads (V3R, V4R, V5R, and V6R) was routinely recorded on admission and every eight hours thereafter for three consecutive days. Thirty-six to 72 hours after the onset of chest pain a 99mtechnetium pyrophosphate scintigraphy and a dynamic flow study were performed to detect right ventricular involvement, which was found in 29 of the 67 patients (43%). ST segment elevation greater than or equal to 1 mm in leads V3R, V4R, V5R, and V6R is a reliable sign of right ventricular involvement. ST segment elevation greater than or equal to 1 mm in lead V4R was found to have the greatest sensitivity (93%) and predictive accuracy (93%). The diagnostic value of a QS pattern in lead V3R and V4R or ST elevation greater than or equal to 1 mm in lead V1 was much lower. ST segment elevation in the right precordial leads was short lived, having disappeared within 10 hours after the onset of chest pain in half of our patients with right ventricular involvement. When electrocardiograms are recorded in patients with an acute inferior wall infarction within 10 hours after the onset of chest pain, additional right ventricular infarction can easily be diagnosed by recording lead V4R.