[Left ventricular hypertrophy and sinus variability in arterial hypertension]

Area of Science:

• Cardiology
• Physiology
• Hypertension Research

Background:

• Conflicting results exist regarding heart rate variability (HRV) in systemic hypertension.
• Left ventricular hypertrophy (LVH) is a common complication of hypertension.
• Understanding HRV alterations in hypertensive patients with or without LVH is crucial for risk stratification.

Purpose of the Study:

• To investigate the impact of left ventricular hypertrophy (LVH) on heart rate variability (HRV) in hypertensive patients.
• To compare HRV parameters between hypertensive patients with normal geometry, concentric remodeling, and LVH.
• To elucidate the autonomic nervous system's modulation in hypertension with varying degrees of cardiac structural changes.

Main Methods:

• Prospective enrollment of 195 hypertensive patients without diabetes, coronary disease, or systolic dysfunction.
• Classification into three groups based on echocardiography: normal geometry, concentric remodeling, and LVH.
• 24-hour Holter ECG recordings for time and frequency domain HRV analysis in patients and 40 controls.

Main Results:

• Hypertensive groups showed decreased global HRV (SDNN, total power) compared to controls.
• Both parasympathetic (pNN50, high frequency) and sympathetic (SDANN, low frequency) HRV indexes were significantly reduced in hypertensive patients.
• Patients with LVH exhibited significantly lower low-frequency power, indicating reduced sympathetic modulation, compared to those with normal geometry or concentric remodeling.

Conclusions:

• Hypertensive patients consistently display reduced parasympathetic indexes.
• The presence of LVH is associated with a more pronounced reduction in sympathetic modulation of HRV.
• HRV assessment provides valuable insights into autonomic dysfunction in hypertension, especially in the context of LVH.