Medina Inojosa, Jose

Background Mitral valve prolapse (MVP) can be associated with ventricular arrhythmias (VA), but little is known about the relationship between VA and exercise in these patients. The aim of this study was to assess the occurrence and severity of VA during exercise tests in patients with MVP, and to explore the association between VA during exercise and the occurrence of arrhythmic events during follow-up. Methods In this multicentre study, 375 patients with MVP (58 (48–69) years, 53% male) who underwent a clinically indicated exercise test were included. Severity of VA during exercise was defined as: (1) no VA, (2) minor VA (premature ventricular contractions ≥5% or non-sustained ventricular tachycardia (nsVT) <120 beats per minute) and (3) major VA (nsVTs ≥120 beats per minute). Results During exercise test, 242 (65%) patients showed no VA, 88 (24%) minor VA and 45 (12%) major VA. Patients with minor and major VAs showed more often bileaflet prolapse and mitral annular disjunction (MAD) than patients with no VA (p<0.001). Over a median follow-up of 101 months (IQR 58–138 months), 35 patients (9%) developed a severe arrhythmic event, defined as sustained VA or ventricular fibrillation, implantation of an implantable cardioverter-defibrillator and VA ablation. At the Kaplan-Meier curve analysis, patients with major VA showed the worst arrhythmic event-free survival (log-rank p<0.001). On multivariable analysis, left ventricular end-systolic diameter, MAD and VA severity during exercise were independently associated with this outcome. Conclusions In patients with MVP, the occurrence of VA during exercise is associated with more advanced mitral valve abnormalities, including MAD, and with higher rates of severe arrhythmic events during follow-up. Performing an exercise test, combined with the clinical and echocardiographic assessments, may therefore offer important complementary information useful for patient management.

Calf muscle pump (CMP) promotes venous return from the lower extremity and contributes to preload and cardiac output. Impaired CMP function may reflect a measure of frailty or cumulative disease burden or may impede cardiac function. The study objective was to test the hypothesis that impaired CMP negatively impacts survival. Consecutive adult patients who underwent venous strain gauge plethysmography at the Mayo Clinic Gonda Vascular Laboratory (January 1, 1998 – December 31, 2011) were assessed for overall survival. Patients with venous incompetence, venous obstruction or unilateral calf pump dysfunction were excluded. Risk of mortality was assessed with Cox proportional hazard ratios and after adjusting for Charlson Comorbidity Index variables. Over the study period, 2728 patients were included in the analysis. Compared to patients with normal CMP, those with impaired CMP were older ( p < 0.001), predominantly female ( p = 0.01) and had higher mean Charlson scores ( p < 0.001). Patients with impaired CMP had a higher mortality rate at 5 (8.9% vs 2.4%), 10 (17.5% vs 5.9%), and 15 years (22.8% vs 8.3%) compared to those with normal CMP ( p < 0.001 for each comparison). Of patients with heart failure, those with impaired CMP had worse survival at each 5-year increment compared to those with normal CMP ( p < 0.05 at each increment). In conclusion, impaired CMP appears to be an independent predictor of poor outcomes after adjusting for variables within the Charlson Comorbidity Index. The association between impaired CMP, heart failure, and mortality may represent a negative impact on circulatory function or a surrogate measure of frailty.