Mitral valve prolapse (MVP) belongs to cardiac disorders characterized by impaired closure of mitral leaflets. We studied adolescent group of patients with MVP suffering from symptomatology that cannot be explained by mitral regurgitation alone. Several studies suggested that symptoms can be explained by autonomic, in particular sympathetic-linked dysfunction. Thus, we assessed non-invasive sympathetic indices of blood pressure and heart rate variability and electrodermal activity (EDA). Fifty-three adolescents with MVP (age: 15.1±0.4 years) and 43 healthy age- and gender-matched adolescents (age: 14.9±0.4 years) were examined. Blood pressure, heart rate and EDA were continuously recorded during 6-min rest. Evaluated parameters were: low frequency band of systolic blood pressure variability, systolic, diastolic and mean blood pressure, mean RR interval, cardiac sympathetic indices: symbolic dynamics (0V%), left ventricular ejection time (LVET), pre-ejection period (PEP), and EDA. Our findings revealed significantly higher systolic, diastolic, and mean blood pressure values, shortened mean RR interval, increased 0V%, and shortened LVET in MVP patients vs. controls (p=0.028, p<0.001, p=0.002, p<0.001, p=0.050, p<0.001; respectively). Our study revealed enhanced cardiovascular sympathetic regulation in adolescent MVP patients. We suggest that evaluation of noninvasive sympathetic parameters could represent potential biomarkers for early diagnosis of cardiovascular complications associated with MVP already at adolescent age.
Respiratory sinus arrhythmia (RSA), i.e. heart rate (HR) variations
during inspiration and expiration, is considered as a noninvasive
index of cardiac vagal control. Mitral valve prolapse (MVP) could
be associated with increased cardiovascular risk; however, the
studies are rare particularly at adolescent age. Therefore, we
aimed to study cardiac vagal control indexed by RSA in adolescent
patients suffering from MVP using short-term heart rate variability
(HRV) analysis. We examined 12 adolescents (girls) with MVP (age
15.9±0.5 years) and 12 age and gender matched controls. Resting
ECG was continuously recorded during 5 minutes. Evaluated HRV
indices were RR interval (ms), rMSSD (ms), pNN50 (%), log HF
(ms2
), peak HF (Hz) and respiratory rate (breaths/min). RR interval
was significantly shortened in MVP group compared to controls
(p=0.004). HRV parameters-rMSSD, pNN50 and log HF were
significantly lower in MVP compared to controls (p=0.017,
p=0.014, p= 0.015 respectively). Our study revealed reduced RSA
magnitude indicating impaired cardiac vagal control in MVP already
at adolescent age that could be crucial for early diagnosis of
cardiovascular risk in MVP.