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Leads V2 (lead + v2)

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Medical Sciences	100%

Selected Abstracts

Diagnostic Significance of a Small Q Wave in Precordial Leads V2 or V3

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010
Tetsuya Katsuno M.D.
Background: An abnormal Q wave is usually defined as an initial depression of the QRS complex having a duration of ,40 ms and amplitude exceeding 25% of the following R wave in any contiguous leads on the 12-lead electrocardiogram (ECG). However, much smaller Q waves are sometimes recorded on the ECG. This study investigated the diagnostic value of the small Q wave recorded in precordial leads V2 or V3 on the ECG. Methods: We investigated 807 consecutive patients who underwent coronary angiography. A small Q wave was defined as any negative deflection preceding the R wave in V2 or V3 with <40-ms duration and <0.5-mV amplitude, with or without a small (<0.1-mV) slurred, spiky fragmented initial QRS deflection before the Q wave (early fragmentation). ECG and coronary angiographic findings were analyzed. Results: The small Q wave was present in 87 patients. Multiple logistic regression analysis revealed that presence of a small Q wave was a strong independent predictor of any coronary artery stenosis or left anterior descending artery (LAD) stenosis (odds ratio = 2.706, 2.902; P < 0.001, < 0.001, respectively). Conclusion: A small Q wave (<40-ms duration and <0.5-mV amplitude) in V2 or V3 with or without early fragmentation significantly predicted the presence of CAD and, especially, significant stenosis in the LAD. Ann Noninvasive Electrocardiol 2010;15(2):116,123 [source]

T-Wave Morphology in Short QT Syndrome

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2009
Olli Anttonen M.D.
Background: Short QT syndrome (SQTS) is an inherited disorder characterized by a short QT interval and vulnerability to ventricular tachyarrhythmias. The diagnostic criteria for this syndrome are not well defined, since there is uncertainty about the lowest normal limits for the corrected QT (QTc) interval. Objective: The aim of this study was to determine whether T-wave morphology parameters are abnormal in short QT subjects and whether those parameters can help in the diagnosis of SQTS. Methods and Results: We describe three families (10 patients) with short QT intervals (QTc 310 ± 32 ms). Seven subjects had suffered serious arrhythmic events and three were asymptomatic. T-wave morphology was assessed using the principal component analysis (PCA). QTc was significantly shorter and T-wave amplitude in lead V2 higher in the short QT subjects compared to healthy controls (n = 149), (P < 0.001 for both). The total cosine of the angle between the main vectors of the QRS and T-wave loops (TCRT) was markedly abnormal among the symptomatic patients with short QT syndrome (n = 7) (TCRT ,0.14 ± 0.55 vs 0.36 ± 0.51, P = 0.019). None of the three asymptomatic patients with short QT but without a history of arrhythmic events had an abnormally low TCRT. Conclusion: Our observations suggest that patients with a short QT interval and a history of arrhythmic events have abnormal T-wave loop parameters. These electrocardiogram (ECG) features may help in the diagnosis of SQTS in addition to the measurement of the duration of QT interval from the 12-lead ECG. [source]

Electrocardiographic and Electrophysiologic Characteristics of Midseptal Accessory Pathways

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2005
SHIH-LING CHANG M.D.
Background: The purpose of the present study was to investigate the electrocardiographic and electrophysiologic characteristics of right midseptal (RMS) and left midseptal (LMS) accessory pathways (APs), and to develop a stepwise algorithm to differentiate RMS from LMS APs. Methods and Results: From May 1989 to February 2004, 1591 patients with AP-mediated tachyarrhythmia underwent RF catheter ablation in this institution, and 38 (2.4%) patients had MS APs. The delta wave and precordial QRS transition during sinus rhythm, retrograde P wave during orthodromic tachycardia, and electrophysiologic characteristic and catheter ablation in 30 patients with RMS APs and 8 patients with LMS APs were analyzed. There was no significant difference in electrophysiologic characteristics and catheter ablation between RMS and LMS APs. The polarity of retrograde P wave during orthodromic tachycardia also showed no statistical difference between patients with RMS and LMS APs. The delta wave polarity was positive in leads I, aVL, and V3 to V6 in patients with RMS and LMS APs. Patients with LMS APs had a higher incidence of biphasic delta wave in lead V1 than patients with RMS APs (80% vs. 15%, P = 0.012). The distributions of precordial QRS transition were different between RMS APs (leads V2; n = 10, V3; n = 7 and V4; n = 3) and LMS APs (leads V1; n = 1 and V2; n = 4) (P = 0.03). The combination of a delta negative wave in lead V1 or precordial QRS transition in lead V3 or V4 had a sensitivity of 90%, specificity of 80%, positive predictive value of 95%, and negative predictive value of 66% in predicting an RMS AP. Conclusions: Delta wave polarity in lead V1 and precordial QRS transition may differentiate RMS and LMS APs. [source]

Intravenous Administration of Class I Antiarrhythmic Drug Induced T Wave Alternans in an Asymptomatic Brugada Syndrome Patient

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2003
KIMIE OHKUBO
A 53-year-old man with an abnormal ECG was referred to the Nihon University School of Medicine. The 12-lead ECG showed right bundle branch block and saddleback-type ST elevation in leads V1,V3 (Brugada-type ECG). Signal-averaged ECG showed positive late potentials. Double ventricular extrastimuli (S1: 500 ms, S2: 250 ms, S3: 210 ms) induced VF. Amiodarone (200 mg/day) was administered for 6 months and programmed ventricular stimulation was repeated. VF was induced again by double ventricular stimuli (S1: 600 ms, S2: 240 ms, S3: 170 ms). Intravenous administration of class Ic antiarrhythmic drug, pilsicainide (1 mg/kg), augmented ST-T elevation in leads V1,V3, and visible ST-T alternans that was enhanced by atrial pacing was observed in leads V2 and V3. Visible ST-T wave alternans disappeared in 15 minutes. However, microvolt T wave alternans was present during atrial pacing at a rate of 70/min without visible ST-T alternans. (PACE 2003; 26:1900,1903) [source]