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[The relationship between anomalies in the autonomous nervous system and left ventricular dysfunction in patients
C Cianfrocca1, F Pelliccia, A Borghi
1Istituto di Patologia Medica, Università degli Studi, Bologna.
Insights
Autonomic nervous system (ANS) dysfunction, particularly impaired parasympathetic control, is common in hypertrophic cardiomyopathy (HC) patients with left ventricular dysfunction. This ANS impairment correlates with the severity of cardiac derangement.
Area of Science:
- Cardiology
- Autonomic Neuroscience
Context:
- Hypertrophic cardiomyopathy (HC) is a complex cardiac condition.
- Autonomic nervous system (ANS) function plays a crucial role in cardiovascular regulation.
- Understanding ANS involvement in HC is vital for patient management.
Purpose:
- To investigate autonomic nervous system (ANS) activity in patients with hypertrophic cardiomyopathy (HC).
- To determine the relationship between ANS function and left ventricular (LV) function in HC patients.
- To differentiate ANS activity based on ejection fraction (EF) in HC.
Summary:
- This study assessed ANS activity in 40 HC patients off-drugs, grouped by ejection fraction (EF > 50% vs. <= 50%).
- Parasympathetic activity was significantly impaired in patients with lower EF (Group B), with abnormalities in Valsalva response, deep breathing HR variability, and standing HR response.
- Sympathetic activity showed some abnormalities in Group B patients, including blood pressure changes during standing and handgrip.
- ANS dysfunction, especially parasympathetic impairment, is common in HC patients with left ventricular dysfunction and appears linked to disease severity.
Impact:
- Findings highlight the prevalence of autonomic dysfunction in HC, particularly in those with impaired left ventricular function.
- The study suggests that ANS abnormalities may serve as indicators of the severity of left ventricular derangement in HC.
- This research contributes to a better understanding of the pathophysiology of HC and potential therapeutic targets.
Abstract:
This study was undertaken to assess autonomic nervous system (ANS) activity and its relation to left ventricular function in 40 patients (mean age: 41 +/- 17 years) with hypertrophic cardiomyopathy (HC), in sinus rhythm, off-drugs. Patients were grouped according to the results of radionuclide angiography: 26 had an ejection fraction > 50% (Group A), whereas 14 had an ejection fraction < or = 50% (Group B). Evaluation of parasympathetic activity showed abnormalities in: heart rate (HR) response during Valsalva (< or = 1.1) in 2 Group A (8%) and 12 Group B (86%) patients (p < 0.001); HR variability during deep breathing (< or = 10 b/min) in 2 Group A (8%) and 14 Group B (100%) patients (p < 0.001); immediate HR response to standing (30:15 < or = 1.0) in 2 Group A (8%) and 6 Group B (43%) patients (p < 0.025). Assessment of sympathetic activity showed abnormalities in: systolic blood pressure fall to standing (> 20 mmHg) in 2 Group B (14%) patients only (NS); diastolic blood pressure response to handgrip (< 10 mmHg) in 4 Group B (29%) patients only (p < 0.025). Thus, in HC: impaired parasympathetic control is common in those patients showing left ventricular dysfunction; concurrent sympathetic abnormality may also occur in this subgroup of patients; ANS dysfunction seems to be merely an epiphenomenon which marks the severity of left ventricular derangement.