Interrelation of QT interval dispersion with echocardiography parameters and variability of cardiac rhythm in patients with hypertrophic cardiomyopathy
Nagaeva G. A., Allaberganov O., Nagaev S. A.
Keywords: variability of cardiac rhythm, hypertrophic cardiomyopathy, qt interval dispersion, EchoCG
Relevance. The search of reliable precursors of fatal ventricular arrhythmias and sudden deaths remains quite an urgent task. One of such precursors of unfavorable events is increased QT interval dispersion. Objective. Study of electromechanical remodeling in interrelation with parameters of cardiac rhythm variability and EchoCG in patients with hypertrophic cardiomyopathy (HCMP). Materials and methods. The study included 33 patients with HCMP, the average age was 34.55±9.87 years. All patients underwent complex clinical and functional investigation: ECG, Holter monitoring and EchoCG. Evaluation of repolarization nonhomogenity was conducted based on QT interval analizis. Results. Depending on the value of the QT interval dispersion the patients were divided in 2 groups: Group I included 11 patients with QT dispersion equal to 40 msec, Group II – 22 patients whose QT dispersion was higher than 40 msec. The analysis showed that the increasing of QT dispersion in HCMP patients leads to increase of the cardialgic syndrome and frequency of syncopal events. QT dispersion >40 msec was characterized by more frequent inversion of T wave in left thoracic leads and more expressed depression of ST wave. EchoCG study demonstrated the trend to development of a restrictive type of diastolic dysf unction (DD) of LV in patients with QT dispersion >40 msec. The greater becomes dispersion of QT, the risk of LV DD is related to activation of sympathetic department of the heart vegetative regulation. Conclusion. Increase of QT dispersion in patients with HCMP is related to increase of rigidity and suppleness of LV. The vegetative imbalance with prevalence of sympathycotonia was more expressed in patients with increased QT dispersion. Increase of chronotropic heart function in HCMP patients is characterized by progress of diastolic dysfunction of restrictive type.
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Nagaeva G. A., Allaberganov O., Nagaev S. A. Interrelation of QT interval dispersion with echocardiography parameters and variability of cardiac rhythm in patients with hypertrophic cardiomyopathy. Russian Heart Failure Journal. 2012;13(3):180-183