Ventricular Arrhythmia Factors in Mitral Valve Prolapse

Abstract

To assess the prevalence of ventricular arrhythmias and late potentials (LPs) in mitral valve prolapse (MVP) and to identify clinical, ECG, and echocardiographic markers of spontaneous ventricular arrhythmias, we studied 58 consecutive patients (mean age 46.6 +/- 17.8 years; 29 males, 29 females) with MVP diagnosed by echocardiography. Patients underwent ambulatory ECG recording (n = 58), exercise stress test (n = 56), signal-averaged ECG (n = 58), and programmed ventricular stimulation (n = 52). Ten patients (17.2%) had spontaneous nonsustained ventricular tachycardia (NSVT), 26 patients (44.8%) had premature ventricular contractions (PVCs), Lown grade > or = 3 during 24-hour ECG, and 19 had Lown grade > or = 3 PVCs during exercise stress test; 13 patients had LPs (22.4%). We provoked sustained VT in one case and NSVT in ten cases. Patients with complex ventricular arrhythmias during 24-hour ECG and exercise stress test were older and more often had mitral regurgitation. There was a statistical correlation between the presence of LPs and spontaneous VT (46.1% vs 8.9%; P < 0.005) and induced ventricular arrhythmias (50% vs 12.8%; P < 0.005). No correlation was found between spontaneous ventricular arrhythmias and thickness or posterior displacement of the mitral valve. In conclusion, complex ventricular arrhythmia (especially VT) and LPs are frequent in MVP. Patient age and mitral regurgitation seem to be determinant factors of complex ventricular arrhythmias in MVP. On signal-averaged ECG, absence of LPs seems to be a good additional marker to identify MVP patients without spontaneous VT. On the other hand, programmed ventricular stimulation does not appear valuable in determining a MVP subgroup with a high risk of ventricular arrhythmias.

Relation Between QT Dispersion and Ventricular Arrhythmias In Uncomplicated Isolated Mitral Valve Prolapse

“…[14][15][16][17] The incidence is reported to increase in complicated cases such as those with an increased anterior and/or posterior leaflet thickness (≥5 mm), and those with severe mitral regurgitation or severe left ventricular systolic dysfunction; moreover, these patients are accepted as having high risk. 18,19 In the current study, we found the incidence to be 48% in uncomplicated cases of MVP and 64% if MVP was accompanied by TVP (p>0.05), a lower incidence for MVP than has been reported earlier. This might reflect our relatively uncomplicated IMVP cases; in fact, there were no patients with severe mitral regurgitation and/or severe left ventricular systolic dysfunction secondary to mitral regurgitation in our study group.…”

Task Force on Sudden Cardiac Death of the European Society of Cardiology

“…In the study of Nishimura et al all 6 MVP patients who died suddenly were found to have redundant leaflets, whereas none of the 231 patients with nonredundant leaflets had SCD [411] . The relationship between the presence and the severity of mitral valve regurgitation and SCD is unclear [409,[411][412][413] . Also, in the study by Zuppiroli mitral valve regurgitation was not an…”

“…Frequent or complex premature ventricular beats were thought to be a risk factor for SCD but their prognostic role was not proven [417] . The SAECG may be helpful in the identification of MVP patients not predisposed to malignant arrhythmia [413] . Inducibility of ventricular tachycardia during PES does not seem to be helpful [413] .…”

ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary

“…The most frequent predictor of cardiovascular mortality is moderate to severe MR and, less frequently, an LV ejection fraction less than 0.50 (294). Echocardiographic evidence of thickened MV leaflets (5 mm or greater) is also a predictor of complications related to MVP (295)(296)(297)(298)(299). In most patients, MVP is associated with a benign prognosis (300,301), with an age-adjusted survival rate for both men and women similar to that of individuals without this entity (302).…”

“…The committee recommends that patients without MR who have leaflet thickening, elongated chordae, left atrial enlargement, or LV dilatation receive endocarditis prophylaxis (295)(296)(297)(298)(299)314) (see Section II-C-1). Patients with MVP and palpitations associated with mild tachyarrhythmias or increased adrenergic symptoms and those with chest pain, anxiety, or fatigue often respond to therapy with beta blockers (315).…”