Letter by Prakash Regarding Article “Impaired Heart Rate Recovery and Chronotropic Incompetence in Patients With Heart Failure With Preserved Ejection Fraction”

Abstract Objective: Exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) is most often attributed to diastolic dysfunction (DD); however, chronotropic incompetence (CI) could also play an important role. We intended to examine whether there are predictive echocardiographic parameters of DD for impaired chronotropic response to exercise. Methods and Results: Patients (n = 143) with unexplained dyspnea and/or exercise intolerance who fulfilled clinical and echocardiographic criteria of HFpEF presence underwent a symptom-limited exercise test using a treadmill (ETT) according to the Bruce protocol. CI was defined as an achieved heart rate reserve (HRR) of ≤ 80%. Comparison of the groups with (n = 98) and without CI (n = 45) did not show any statistically significant difference regarding demographic and clinical character-ristics except for use of beta blockers (BB) that were more frequently present (p = 0.012) in patients with CI in comparison with those without. Patients with CI had a higher mean E-wave velocity, E/A ratio, increased E/E‵ septal, lateral as well as average ratio and abnormal IVRT/TE-e‵ index all consistent with elevated LV filling pressures. E/E‵ average ratio > 15 was statistically insignificantly more frequently present in patients with CI. In addition, by multivariate stepwise regression analysis value of E‵ septal (β = 3.697, 95%CI 0.921–6.473, p = 0.009) along with use of BB, current smoking and basal heart rate appeared as statistically significant independent predictors of lower HRR %. Conclusion: Patients with HFpEF frequently have chronotropic incompetence to graded exercise which may partly be predicted with echocardiographic parameters that are consistent with elevated LV filling pressures.

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Heart Rate–Induced Myocardial Ca 2+ Retention and Left Ventricular Volume Loss in Patients With Heart Failure With Preserved Ejection Fraction

Journal of the American Heart Association ◽

10.1161/jaha.120.017215 ◽

2020 ◽

Vol 9 (17) ◽

Author(s):

Daniel N. Silverman ◽

Mehdi Rambod ◽

Daniel L. Lustgarten ◽

Robert Lobel ◽

Martin M. LeWinter ◽

...

Keyword(s):

Heart Failure ◽

Heart Rate ◽

Ejection Fraction ◽

Sinus Rhythm ◽

Left Ventricular ◽

Atrial Pacing ◽

Preserved Ejection Fraction ◽

Volume Loss ◽

Heart Rates ◽

Patients With Heart Failure

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca 2+ overload caused by increased myocardial Na + levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension. Methods and Results In 22 fully sedated and instrumented patients (12 controls and 10 patients with HFpEF) in sinus rhythm with a preserved ejection fraction (≥50%) we assessed left‐sided filling pressures and volumes in sinus rhythm and with atrial pacing (95 beats per minute and 125 beats per minute) before atrial fibrillation ablation. Coronary sinus blood samples and flow measurements were also obtained. Seven women and 15 men were studied (aged 59±10 years, ejection fraction 61%±4%). Patients with HFpEF had a history of hypertension, dyspnea on exertion, concentric LV remodeling and a dilated left atrium, whereas controls did not. Pacing at 125 beats per minute lowered the mean LV end‐diastolic pressure in both groups (controls −4.3±4.1 mm Hg versus patients with HFpEF −8.5±6.0 mm Hg, P =0.08). Pacing also reduced LV end‐diastolic volumes. The volume loss was about twice as much in the HFpEF group (controls −15%±14% versus patients with HFpEF −32%±11%, P =0.009). Coronary venous [Ca 2+ ] increased after pacing at 125 beats per minute in patients with HFpEF but not in controls. [Na + ] did not change. Conclusions Higher resting heart rates are associated with lower filling pressures in patients with and without HFpEF. Incomplete relaxation and LV filling at high heart rates lead to a reduction in LV volumes that is more pronounced in patients with HFpEF and may be associated with myocardial Ca 2+ retention.

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