LV Diastolic Dysfunction and Inappropriate LV Filling Pressure Escalation: The Core of Exercise Intolerance in Heart...

Area of Science:

• Cardiology
• Exercise Physiology
• Echocardiography

Background:

• Exercise intolerance is a primary symptom across all heart failure (HF) phenotypes.
• Understanding determinants of exercise capacity is crucial for managing HF patients.

Purpose of the Study:

• To investigate factors influencing exercise capacity in chronic stable heart failure.
• To analyze determinants across reduced, mildly reduced, preserved, and recovered ejection fraction (EF).

Main Methods:

• Combined cardiopulmonary exercise testing and exercise stress echocardiography in ambulatory HF patients.
• Defined impaired exercise capacity as peak oxygen consumption <14 mL/kg/min.
• Defined ventilatory inefficiency as minute ventilation/carbon dioxide production ratio >34.

Main Results:

• Diastolic dysfunction independently predicted impaired exercise capacity (OR, 3.847).
• Resting global longitudinal strain (GLS) correlated with ventilatory inefficiency (OR, 1.404).
• Peak medial E/e' to cardiac output (CO) ratio was linked to impaired capacity (OR, 3.478); peak GLS related to ventilatory inefficiency (OR, 1.403).

Conclusions:

• The peak medial E/e' to CO ratio, assessing exertional left ventricular filling pressure, is a key determinant of exercise capacity in diverse HF phenotypes.
• This non-invasive echocardiographic measure offers significant insights into exercise limitations in heart failure.