Left ventricular long-axis function in myasthenia gravis

Abstract

Myasthenia gravis (MG) primarily affects skeletal muscles, but influence on cardiac function has been suggested. The aim of this study was to assess left ventricular long-axis function in MG patients compared to healthy controls, and to examine whether any MG-related heart involvement was influenced by the acetylcholine-esterase inhibitor pyridostigmine. We found that early diastolic atrioventricular-plane velocity and tissue Doppler peak systolic strain was lower in MG patients than in controls before pyridostigmine. The differences disappeared following administration of pyridostigmine. Also, tissue velocities at systole and early diastole tended to be lower in patients before pyridostigmine. In multivariate analyses adjusting for between-group differences in blood pressure, MG was no longer associated with lower longaxis function. Conventional echocardiographic measures of left ventricular diastolic and systolic function did not differ between groups. In conclusion, this study, using modern tissue Doppler imaging as well as conventional echocardiography, could not demonstrate definite MG-related cardiac involvement in a group of MG patients without known cardiac disease, but indicates that pyridostigmine-responsive MG-related alterations in cardiac muscle function exist in MG patients.

A Broken Heart: Cardiac Arrest As the Initial Presentation of Myasthenic Crisis

“…Association between MG and EKG abnormalities has also been investigated in several studies [7][8][9]. It was noted that ST depression, T-wave inversion, AV and right bundle branch block, as well as atrial fibrillation, have all been described.…”

“…In a study by Furlund Owe et al, EKG changes in 143 patients with MG were investigated and it was discovered that there was a shorter PR interval in patients with MG versus control group (156 ms vs 170 ms, p=0.047); however, the PR interval in MG group stayed within limits of normal (120-200 ms) [9]. In our patient, initial EKG demonstrated significantly shorted PR interval (96 ms) without delta wave or pre-excitation syndrome.…”

The Role of Acalypha Indica Linn. Extract on Heart Rates With Myasthenia Gravis Rat Model

“…A few studies were carried out to investigate cardiac involvement in patients with MG. Some reported non-specific ECG changes, Doppler imaging, and conventional echocardiography [29]. Another study demonstrated a reduced global heart ejection fraction in 40% of MG patients without known cardiac disease after exercise interpreted as a true association between MG and heart disease [30].…”

Cardiac autonomic function in patients with myasthenia gravis: analysis of the heart-rate variability in the time-domain

“…[13] A few studies were carried out to investigate cardiac involvement in patients with MG. Some reported nonspecific electrocardiographic (ECG) changes, Doppler imaging and conventional echocardiography, [14] while others reported variable results, which varied from asymptomatic specific ECG changes (as abnormalities of the STI, [15] dispersion of QT and T wave alternans [16] ), giant diffuse T waves, to clinically manifest abnormalities (as conduction disturbances, atrioventricular dissociation, wide QRS, [17] syncopal attacks, orthostatic hypotension, impaired heart-rate variability (HRV) [18,19] ). These significant cardiac manifestations were reported in patients with severe stages of MG and in the presence of thymoma.…”