What is the clinical evidence from this study?

Study design: Observational. Population: Arrhythmogenic right ventricular cardiomyopathy (n=109). Intervention: Right ventricular mechanical dispersion vs. Lower mechanical dispersion. Primary outcome: Ventricular arrhythmias (VT/VF) (OR 1.66, 95% CI 1.06-2.58, p=<0.03).

March 15, 2011Open Access

Right ventricular mechanical dispersion is related to malignant arrhythmias: a study of patients with arrhythmogenic right ventricular cardiomyopathy and subclinical right ventricular dysfunction

Q: What are the key findings of this study?

Right ventricular mechanical dispersion predicted ventricular arrhythmias in patients with ARVC (OR 1.66; 95% CI 1.06-2.58; P<0.03) and was increased in asymptomatic mutation carriers.

Key Result

Right ventricular mechanical dispersion predicted ventricular arrhythmias in patients with ARVC (OR 1.66; 95% CI 1.06-2.58; P<0.03) and was increased in asymptomatic mutation carriers.

Study Design

Type

Observational (n=109)

PICO

Population

109 individuals, comprising 42 symptomatic ARVC patients, 27 asymptomatic mutation carriers, and 40 healthy controls.

Exposure / Comparator

Right ventricular mechanical dispersion vs Lower mechanical dispersion

Primary Outcome

Ventricular arrhythmias (VT/VF) — OR 1.66 (1.06-2.58), p=<0.03

Main Result

Odds Ratio: 1.66 (95% CI 1.06–2.58)

p-value: p=<0.03

Abstract

AIMS: We evaluated if right ventricular (RV) mechanical dispersion by strain was related to ventricular arrhythmias (VT/VF) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and if mechanical dispersion was increased in so far asymptomatic mutation carriers. METHODS AND RESULTS: We included 69 patients, 42 had symptomatic ARVC and 27 were mutation positive asymptomatic family members. Forty healthy individuals served as controls. Myocardial strain was assessed in 6 RV and 16 left ventricular (LV) segments. Contraction duration (CD) in 6 RV and 16 LV segments were measured as the time from onset R on electrocardiogram to maximum myocardial shortening in each segment. The standard deviation of CD was defined as mechanical dispersion. Mechanical dispersion was more pronounced in ARVC patients with arrhythmias compared with asymptomatic mutation carriers and healthy individuals in RV 52(41,63) vs. 35(23,47) vs. 13(9,19)ms, P < 0.001. Mechanical dispersion was more pronounced in asymptomatic mutation carriers compared with healthy individuals (P < 0.001). Right ventricular mechanical dispersion predicted VT/VF in a multivariate logistic regression analysis odds ratio (OR), 1.66 (95% confidence interval (CI) 1.06-2.58), P < 0.03. Right ventricular and LV function by strain were reduced in symptomatic ARVC patients and correlated significantly (R = 0.81, P < 0.001). Right ventricular and LV strain were reduced in asymptomatic mutation carriers compared with healthy individuals (P < 0.001). CONCLUSION: Right ventricular mechanical dispersion was pronounced in patients with ARVC with VT/VF. Right ventricular mechanical dispersion was present in asymptomatic mutation carriers and may be helpful in risk stratification. Right ventricular and LV function correlated in ARVC patients implying that ARVC is a biventricular disease.