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[Left ventricular hypertrophy and sinus variability in arterial hypertension]
M Galinier1, A Pathak, J Fourcade
1Fédération des services de cardiologie, centre hospitalo-universitaire de Rangueil, Toulouse.
Insights
Heart rate variability (HRV) is reduced in hypertension, particularly sympathetic modulation in patients with left ventricular hypertrophy (LVH). This study clarifies HRV alterations in hypertensive individuals with and without LVH.
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.
Background:
Previous studies of heart rate variability (HRV) in systemic hypertension have yielded conflicting results. We sought to assess the alterations of HRV in hypertensive patients with or without left ventricular hypertrophy (LVH).
Methods:
195 hypertensive patients in sinus rhythm, mean age 53 +/- 11 years, without diabetes mellitus, nor symptomatic coronary disease or systolic dysfunction, were prospectively enrolled. Echocardiographic examination allowed their subdivision in 3 groups: normal geometry (112), concentric remodeling (43) and LVH (40). Time and frequency domain measures of HRV were obtained from 24 h Holter ECG recordings in all patients as in 40 control subjects.
Results:
In comparison with control subjects, the 3 hypertensive groups presented a significant decrease of SDNN and total frequency power both indexes of global HRV; a significant decrease of pNN50 and high frequency power, indexes of HRV reflecting parasympathetic tone, and a significant decrease of SDANN and low frequency power, indexes reflecting sympathetic modulation of HRV. Comparisons among the three hypertensive groups showed that patients with LVH had significantly (p < 0.05) lower low frequency power (5.5 +/- 1.0 Ln m2) than patients with left ventricular normal geometry (5.9 +/- 0.8 Ln m2) or concentric remodeling (5.9 +/- 0.9 Ln m2).
Conclusion:
Assessment of HRV in hypertensive patients shows a constant decrease of parasympathetic indexes and a more markedly reduction of sympathetic parameters in presence of LVH.