PW320 Association between heart rate and decrease of left ventricular ejection fraction after stress in normal perfusion imaging

In the failing human myocardium, both impaired calcium homoeostasis and alterations in the levels of contractile proteins have been observed, which may be responsible for reduced contractility as well as diastolic dysfunction. In addition, levels of a key protein in calcium cycling, i.e. the sarcoplasmic reticulum Ca2+-ATPase, and of the α-myosin heavy chain have been shown to be enhanced by treatment with etomoxir, a carnitine palmitoyltransferase inhibitor, in normal and pressure-overloaded rat myocardium. We therefore studied, for the first time, the influence of long-term oral application of etomoxir on cardiac function in patients with chronic heart failure. A dose of 80 mg of etomoxir was given once daily to 10 patients suffering from heart failure (NYHA functional class II–III; mean age 55±4 years; one patient with ischaemic heart disease and nine patients with dilated idiopathic cardiomyopathy; all male), in addition to standard therapy. The left ventricular ejection fraction was measured echocardiographically before and after a 3-month period of treatment. Central haemodynamics at rest and exercise (supine position bicycle) were defined by means of a pulmonary artery catheter and thermodilution. All 10 patients improved clinically; no patient had to stop taking the study medication because of side effects; and no patient died during the 3-month period. Maximum cardiac output during exercise increased from 9.72±1.25 l/min before to 13.44±1.50 l/min after treatment (P < 0.01); this increase was mainly due to an increased stroke volume [84±7 ml before and 109±9 ml after treatment (P < 0.01)]. Resting heart rate was slightly reduced (not statistically significant). During exercise, for any given heart rate, stroke volume was significantly enhanced (P < 0.05). The left ventricular ejection fraction increased significantly from 21.5±2.6% to 27.0±2.3% (P < 0.01). In acute studies, etomoxir showed neither a positive inotropic effect nor vasodilatory properties. Thus, although the results of this small pilot study are not placebo-controlled, all patients seem to have benefitted from etomoxir treatment. Etomoxir, which has no acute inotropic or vasodilatory properties and is thought to increase gene expression of the sarcoplasmic reticulum Ca2+-ATPase and the α-myosin heavy chain, improved clinical status, central haemodynamics at rest and during exercise, and left ventricular ejection fraction.

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Systolic left ventricular dysfunction in patients with clinically suspected myocarditis

Proceedings of the National Academy of Sciences of Belarus Medical series ◽

10.29235/1814-6023-2020-17-4-452-460 ◽

2020 ◽

Vol 17 (4) ◽

pp. 452-460

Author(s):

N. P. Mitkovskaya ◽

E. M. Balysh ◽

T. V. Statkevich ◽

N. A. Ladygina ◽

E. B. Petrova ◽

...

Keyword(s):

Heart Rate ◽

Left Ventricular Ejection Fraction ◽

Ejection Fraction ◽

Left Ventricular Systolic Dysfunction ◽

Systolic Dysfunction ◽

Left Ventricular ◽

Ventricular Ejection ◽

Left Ventricular Ejection ◽

Ventricular Systolic Dysfunction ◽

Ventricular Ejection Fraction

The aim of the study was to investigate the features of clinically suspected myocarditis complicated by the left ventricular systolic dysfunction development. 93 patients with clinically suspected myocarditis were examined. The average age was 36.63 ± 1.15 years. In 43.01 % of patients the disease was accompanied by a decrease in left ventricular systolic function. In the group of patients with left ventricular systolic dysfunction in comparison with those with preserved left ventricular ejection fraction, a significantly lower proportion of men (75 % versus 81 %, respectively, χ2 = 9.3, p < 0,01) and a higher average group age (40.7 ± 1.87 versus 33.6 ± 1.3 years, respectively, p < 0,01) were revealed. The course of the disease in patients with left ventricular systolic dysfunction was characterized by a more frequent development of rhythm disturbances (65 % versus 43.3 %, respectively, χ2 = 4.3, p < 0,05) and a higher heart rate at admission (94.5 (75‒100) and 85 (70‒89) beats per minute, respectively, p = 0.006). The structural and functional state of the heart according to echocardiography in patients with a reduced left ventricular ejection fraction versus comparison group was characterized by larger heart chambers sizes, more pronounced violations of local left ventricular contractility, more frequent involvement of the right ventricle in the pathological process (56.3 % versus 22.2 %, respectively, χ2 = 6.4, p < 0,05). The relationships between the left ventricular ejection fraction Весці Нацыянальнай акадэміі навук Беларусі. Серыя медыцынскіх навук. 2020. Т. 17, № 4. C. 452–460 453 and the patient’s age (r = ‒0.36), the value of the heart rate at admission (r = ‒0.32), the severity of heart failure at admission, the degree of impaired local contractility of the left ventricle, the degree of right ventricular function (TAPSE, r = 0.58), the severity of myocardial fibrosis according to cardiovascular magnetic resonance imaging (r = ‒0.32) were revealed.

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