Ventilatory Efficiency Is Reduced in People With Hypertension During Exercise

Area of Science:

• Cardiology
• Pulmonary Medicine
• Exercise Physiology

Background:

• Elevated minute ventilation/volume of expired CO2 (VE/VCO2) slope is a known prognostic indicator in heart failure.
• Hypertension is common in heart failure with preserved ejection fraction, but the VE/VCO2 slope in primary hypertension is not well understood.
• A spectrum of ventilatory inefficiency may exist in cardiovascular disease, reflecting physiological responses to exercise.

Purpose of the Study:

• To evaluate the VE/VCO2 slope in patients with primary hypertension compared to normotensive controls.
• To assess if ventilatory inefficiency is present in individuals with hypertension but without diagnosed heart failure.

Main Methods:

• Ramped cardiovascular pulmonary exercise tests were conducted on 55 hypertensive patients and 24 normotensive controls.
• The VE/VCO2 slope was measured during exercise tests to peak oxygen consumption.
• Groups were matched for age, peak oxygen consumption, and sex.

Main Results:

• No significant differences were found in age, BMI, or peak oxygen consumption between hypertensive and normotensive groups.
• The VE/VCO2 slope was significantly elevated in the hypertensive group (31.8±4.5) compared to controls (28.4±3.4) (P=0.002).
• Only 27% of hypertensive patients had a normal VE/VCO2 slope, versus 71% in the control group.

Conclusions:

• Ventilatory efficiency is impaired in individuals with hypertension, even without a heart failure diagnosis.
• Hypertension is associated with an elevated VE/VCO2 slope, indicating reduced ventilatory efficiency during exercise.
• Further research is needed to determine if elevated VE/VCO2 slopes in hypertensive patients predict future heart failure development.