Is QRS Duration a Reliable Parameter in Discriminating between Supraventricular and Ventricular Arrhythmias?

The development of slow conduction during the first hours of acute transmural myocardial infarction (ATMI) was studied by signal-averaged electrocardiograms (SAE) in 19 adult anesthetized sheep. SAEs were recorded before and after intravenous infusions of lidocaine and bretylium were begun and 10, 30, and 60 min after ATMI produced by ligation of the left anterior descending and second diagonal coronary arteries. Four sheep died promptly of ventricular tachyarrhythmias; two others developed sustained ventricular arrhythmias, which precluded additional data. Biphasic changes in QRS duration, root mean square voltage of the terminal 40 ms of the QRS complex, and duration of terminal low-amplitude (less than 30 microV) signal were observed. Peak changes in conduction occurred 30 min after infarction and regressed toward baseline thereafter. At 30 min, all animals developed late potentials, which were defined as signals that exceeded both after-drug QRS duration and duration of terminal low-amplitude signal less than 30 microV by more than two standard deviations. At 60 min, only 3 of 13 (23%) animals had late potentials. Conduction is slowest 30 min after ATMI in sheep but may not be related to development of ventricular arrhythmias. In five of six sheep (83%), ventricular arrhythmias occurred within 15 min of infarction before peak slowing was observed by SAE.

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QRS Complex Enlargement as a Predictor of Ventricular Arrhythmias in Patients Affected by Surgically Treated Tetralogy of Fallot: A Comprehensive Literature Review and Historical Overview

ISRN Cardiology ◽

10.1155/2013/782508 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Pier Paolo Bassareo ◽

Giuseppe Mercuro

Keyword(s):

Tetralogy Of Fallot ◽

Ventricular Arrhythmias ◽

Surgical Repair ◽

Strong Predictor ◽

Term Survival ◽

Qrs Prolongation ◽

Life Threatening ◽

Qrs Duration ◽

The Impact

Tetralogy of Fallot (TOF) is a congenital heart disease frequently treated by surgical repair to relieve symptoms and improve survival. However, despite the performing of an optimal surgical repair, TOF patients are at times characterized by a poor long-term survival rate, likely due to cardiac causes such as ventricular arrhythmias, with subsequent sudden death. In the 80s it was irrefutably demonstrated that QRS prolongation ≥180 msec at basal electrocardiogram is a strong predictor for refining risk stratification for ventricular tachycardia in these patients. The aim of this research was to undertake a review of all studies conducted to assess the impact of QRS duration on the development of life-threatening ventricular arrhythmias in repaired TOF subjects.

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Abstract 15331: Ventricular Conduction and Repolarization Prolongation Noted During Right Ventricular Pacing as Predictors of Ventricular Arrhythmias and Cardiac Mortality in Subjects With Cardiomyopathy

Circulation ◽

10.1161/circ.132.suppl_3.15331 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Freddy Del Carpio ◽

Shahyar M Gharacholou ◽

Christopher S Scott ◽

Vuyisille Nkomo ◽

Francisco Lopez-Jimenez ◽

...

Keyword(s):

Right Ventricular ◽

Ventricular Arrhythmias ◽

Total Mortality ◽

Functional Class ◽

Qtc Interval ◽

Right Ventricular Pacing ◽

Study Results ◽

Qrs Duration ◽

Rv Pacing ◽

Ventricular Conduction

Introduction: Clinical predictive value of transient prolonged ventricular conduction and repolarization during right ventricular (RV) pacing have not been studied. Hypothesis: Ventricular conduction and repolarization prolongation during RV pacing predict risk of arrhythmic and mortality events. Methods: Electrophysiology studies in 501 patients with cardiomyopathy (CM) were reviewed. Duration changes of QRS and QT interval during pacing from the RV apex were measured. Subjects were followed up for a mean of 3.2 years for arrhythmic events and total mortality. Results: Participants had a mean age 65 yrs, 80% male, 74% funcional class II or III, and a mean EF of 33.1%. A paced QRS duration > 190 ms was associated with more severe CM and in multi-variable analysis it was associated with a 3.5 times higher risk of ventricular arrhythmias or appropriate defibrillator therapy (HR 3.5, 95% CI 2.3-5.4, p<0.01) and 2.6 times higher risk of total mortality or arrhythmic events (HR 2.6, 95% CI 2.3-3.4, p<0.01) compared to a paced QRS duration <190 ms, independent of baseline EF or baseline QRS duration, and after adjustment for electrophysiology study results, baseline functional class, type of cardiomyopathy and other relevant clinical factors. Similarly a QTc interval during RV pacing > 620 ms was associated with a 2.7 times higher risk of arrhythmic events compared to a QTc interval during RV pacing < 620 ms. Conclusions: Prolongation of ventricular conduction (QRS > 190 ms) and repolarization (QTc > 620 ms) observed during RV pacing in subjects with CM are associated with higher risk of arrhythmic events, defibrillator therapies and all-cause mortality.

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High-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxer dogs

Ciência Rural ◽

10.1590/s0103-84782013000600025 ◽

2013 ◽

Vol 43 (6) ◽

pp. 1102-1106

Author(s):

Evandro Zacché Pereira ◽

Thais Cristine Alves Assumpção ◽

Ana Paula Gering ◽

Fábio Nelson Gava ◽

Edna Mireya Gómez Ortiz ◽

...

Keyword(s):

High Resolution ◽

Right Ventricular ◽

Ventricular Arrhythmias ◽

Arrhythmogenic Right Ventricular Cardiomyopathy ◽

Systolic Dysfunction ◽

Qrs Complex ◽

Ventricular Cardiomyopathy ◽

Echocardiographic Examination ◽

Qrs Duration ◽

Boxer Dogs

To evaluate the reliability of high-resolution electrocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers, 20 dogs with no structural cardiac alterations at echocardiographic examination were grouped on the basis of frequency of ventricular arrhythmias, evaluated by 24-hour ambulatory ECG, and undergoing a high-resolution electrocardiography. High frequency QRS duration, duration of terminal QRS complex less than 40µV (LAS40) and root mean square voltage of the terminal 40 milliseconds of the QRS complex (RMS40) were measured. Differences in high-resolution ECG variables were not observed between groups. Therefore, the results of this investigation suggest that high-resolution electrocardiography is not a useful method for the diagnosis of arrhythmogenic right ventricular cardiomyopathy in Boxers without detectable myocardial alterations or systolic dysfunction.

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QRS duration and prediction of mortality in patients undergoing risk stratification for ventricular arrhythmias

The American Journal of Cardiology ◽

10.1016/s0002-9149(03)00886-5 ◽

2003 ◽

Vol 92 (7) ◽

pp. 798-803 ◽

Cited By ~ 47

Author(s):

Vidyasagar Kalahasti ◽

Vijay Nambi ◽

David O Martin ◽

Cathy T Lam ◽

David Yamada ◽

...

Keyword(s):

Risk Stratification ◽

Ventricular Arrhythmias ◽

Prediction Of Mortality ◽

Qrs Duration

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A territory-wide study of arrhythmogenic right ventricular cardiomyopathy patients from Hong Kong

10.1101/2021.11.17.21266304 ◽

2021 ◽

Author(s):

Ishan Lakhani ◽

Jiandong Zhou ◽

Sharen Lee ◽

Ka Hou Christien Lee ◽

Keith Sai Kit Leung ◽

...

Keyword(s):

Hong Kong ◽

Ejection Fraction ◽

Right Ventricular ◽

Ventricular Arrhythmias ◽

Arrhythmogenic Right Ventricular Cardiomyopathy ◽

Hospital Setting ◽

Ventricular Cardiomyopathy ◽

All Cause Mortality ◽

Qrs Duration ◽

New Onset

Background: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a hereditary disease characterized by fibrofatty infiltration of the right ventricular myocardium that predisposes affected patients to malignant ventricular arrhythmias, dual-chamber cardiac failure and sudden cardiac death (SCD). The present study aims to investigate the risk of detrimental cardiovascular events in an Asian population of ARVC/D patients, including the incidence of malignant ventricular arrhythmias, new-onset heart failure with reduced ejection fraction (HFrEF), as well as long-term mortality. Methods and Results: This was a territory-wide retrospective cohort study of patients diagnosed with ARVC/D between 1997 and 2019 in Hong Kong. This study consisted of 109 ARVC/D patients (median age: 61 [46-71] years; 58% male). Of these, 51 and 24 patients developed incident VT/VF and new-onset HFrEF, respectively. Five patients underwent cardiac transplantation, and 14 died during follow-up. Multivariate Cox regression identified prolonged QRS duration as a predictor of VT/VF (p < 0.05). Female gender, prolonged QTc duration, the presence of epsilon waves and T-wave inversion (TWI) in any lead except aVR/V1 predicted new-onset HFrEF (P < 0.05. The presence of epsilon waves, in addition to the parameters of prolonged QRS duration and worsening ejection fraction predicted all-cause mortality (p<0.05). Clinical scores were developed to predict incident VT/VF, new-onset HFrEF and all-cause mortality, and all were significantly improved by machine learning techniques. Conclusion: Clinical and electrocardiographic parameters are important for assessing prognosis in ARVC/D patients and should in turn be used in tandem to aid risk stratification in the hospital setting.

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