Introduction:
With improved survival of sudden cardiac death in arrhythmogenic right ventricular cardiomyopathy (ARVC), progressive heart failure is increasingly recognized. Cardiopulmonary exercise testing (CPET) can play a role in prognostication. However, correlation of morphologic disease severity and exercise capacity is lacking.
Hypothesis:
Increased RV size and decreased RV function measured by two-dimensional echocardiography (2D echo) are associated with impaired exercise capacity parameters (peak oxygen consumption (pVO
2
) and ventilator efficiency (VE/VCO
2
slope)).
Methods:
We retrospectively examined 21 patients who underwent 25 echocardiography and cardiopulmonary exercise testing (CPET) studies within 6 months of each other. A Spearman rank correlation was used to determine the relationship between RV dimensions and CPET parameters. Seven (28%) had submaximal effort defined as respiratory exchange ratio <1.05 and were excluded in the analysis of pVO
2
.
Results:
Patients’ mean age was 44 ± 11 years and 28% were women. Despite more than half of patients (54%) being New York Heart Association Class I, mean pVO
2
was decreased at 19 ± 5 mL/kg per minute (63% ± 22% predicted for age and sex). There was a moderate negative correlation between pVO
2
and RV basal diameter (
r
s
= -0.46,
p
=0.05) and RV area in diastole (
r
s
= -0.55,
p
=0.02). There was no significant correlation between RV size or function with VE/VCO
2
slope.
Conclusion:
In this small study of ARVC patients, abnormalities on echo including increased RV basal diameter and RV diastolic area were associated with worse pVO
2
but not VE/VCO
2
slope. These findings suggest that RV structural abnormalities are related to reduced oxygen uptake on CPET, and larger studies are warranted to investigate the prognostic value and clinical course of ARVC patients with regards to the development of heart failure.
Exercise Testing in Asymptomatic Gene Carriers Exposes a Latent Electrical Substrate of Arrhythmogenic Right Ventricular Cardiomyopathy
