Radionuclide Assessment of Cardiac Function and Dyssynchrony in Children with Idiopathic Ventricular Tachycardia.
BACKGROUND
The aim of the study was to evaluate the impact of idiopathic ventricular tachycardia and premature ventricular beats on cardiac function and dyssynchrony and to elucidate relationships between data of scintigraphic and intracardiac electrophysiology studies (EPSs).


METHODS
The study comprised 64 patients with idiopathic ventricular arrhythmias (VAs; median age of 14 years ranging from 8 to 18 years). The control group comprised 20 patients (median age of 12 ranging from 7 to 16 years) without cardiac arrhythmias. EPS and radiofrequency ablation (RFA) procedure for VA were performed in 21 children according to indications. The functional state of both ventricles was assessed by gated blood pool single photon emission computer tomography (GBP-SPECT) before and after RFA in all patients.


RESULTS
Patients with VA had local areas of asynchronous myocardial contraction (AMC). Compared with the control group, VA patients had significantly higher values of end-diastolic volume, end-systolic volume, and lower contractility indices. Negative association was found between total numbers of AMC areas and cardiac contractility indices. Ectopic foci localization, determined based on EPS data, was associated with AMC areas topography based on GBP-SPECT. RFA procedure significantly improved cardiac contractility indices; AMC areas completely disappeared or decreased compared with the preoperative conditions.


CONCLUSIONS
In VA patients, AMC areas were localized mostly in the right ventricle. Comparison of the results of GBP-SPECT and EPS studies showed a relationship between AMC localizations and ectopic foci topography. The fact that AMC areas disappeared after RFA supports the hypothesis stating that the presence of AMC areas is a scintigraphic symptom of ectopic focus.
Nuclear Medicine Department, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Tomsk, Russia.|National Research Tomsk Polytechnic University, Russian Federation, Tomsk, Russia.
Konstantin V
KV
Zavadovsky
Nuclear Medicine Department, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Tomsk, Russia.
Victor V
VV
Saushkin
Department of Surgical Treatment of Cardiac Rhythm Disorders and Pacing, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Tomsk, Russia.
Mikhail S
MS
Khlynin
Department of Surgical Treatment of Cardiac Rhythm Disorders and Pacing, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Tomsk, Russia.
Sergey V
SV
Popov
Nuclear Medicine Department, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Tomsk, Russia.|National Research Tomsk Polytechnic University, Russian Federation, Tomsk, Russia.
Yuri B
YB
Lishmanov
D000293:Adolescent; D002648:Child; D022062:Electrophysiologic Techniques, Cardiac; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology; D017180:Tachycardia, Ventricular / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon; D018879:Ventricular Premature Complexes / Q000503:physiopathology*
gated blood pool SPECT; ventricular arrhythmia