Left ventricular hypertrophy and the 'cardiogenic reflex' in man

Area of Science:

• Cardiology
• Physiology
• Hypertension Research

Background:

• Cardiac receptors normally regulate sympathetic activity, renin, and vasopressin secretion.
• These reflexes are crucial for maintaining blood pressure and blood volume homeostasis.
• Left ventricular hypertrophy (LVH) is known to affect cardiovascular function.

Purpose of the Study:

• To investigate the impact of left ventricular hypertrophy (LVH) on cardiac reflexes.
• To determine if LVH, regardless of its cause, impairs cardiogenic reflex function.
• To explore the reversibility of impaired cardiac reflexes following LVH regression.

Main Methods:

• Assessing cardiogenic reflex function in subjects with LVH due to hypertension and physical training.
• Evaluating blood pressure and blood volume homeostasis in these subjects.
• Monitoring reflex function changes after interventions aimed at reducing LVH (cessation of training, antihypertensive treatment).

Main Results:

• Cardiac reflexes were found to be significantly depressed in individuals with LVH, irrespective of the cause (hypertension or training).
• This impairment in cardiogenic reflex function was associated with disruptions in blood pressure homeostasis.
• Regression of LVH, achieved through training cessation or antihypertensive therapy, led to a marked improvement in cardiac reflex function.

Conclusions:

• LVH adversely affects the 'afferent' function of the heart, impairing cardiac reflexes.
• Both pathological (hypertension-induced) and physiological (training-induced) hypertrophy have similar negative effects on these reflexes.
• The adverse effects of LVH on cardiac reflex function are reversible, with restoration of function upon regression of hypertrophy.