Regional cardiac sympathetic denervation in patients with ventricular tachycardia in the absence of coronary artery disease.
OBJECTIVE
The aim of this study was to determine whether patients with ventricular arrhythmias in the absence of coronary artery disease also have abnormalities in sympathetic innervation.


BACKGROUND
We have previously shown by cardiac sympathetic scintigraphy using iodine-123-metaiodobenzylguanidine (I-123-MIBG) that patients with ventricular tachycardia after myocardial infarction have regional cardiac sympathetic denervation. It is not known whether patients with ventricular tachycardia in the absence of coronary artery disease also have regional cardiac sympathetic denervation.


METHODS
We performed cardiac I-123-MIBG and thallium-201 single-photon emission computed tomographic (SPECT) scans at rest in 18 patients (mean age 47 +/- 18 years) with cardiomyopathy (n = 6), left ventricular hypertrophy (n = 1), valvular disease (n = 2) or a structurally normal heart (n = 9) who presented with monomorphic (n = 15) or polymorphic (n = 3) ventricular tachycardia. These scans were compared with scans in 12 control patients without ventricular tachycardia (mean age 30 +/- 17 years) who had cardiomyopathy (n = 3) or a structurally normal heart (n = 9). Cardiac sympathetic denervation was defined as myocardial areas having thallium uptake with reduced or absent I-123-MIBG uptake.


RESULTS
Twelve (67%) of 18 patients with ventricular tachycardia had regional cardiac sympathetic denervation compared with 1 (8%) of 12 patients who did not have ventricular tachycardia (p = 0.002). In the nine patients with a structurally normal heart and ventricular tachycardia, five (55%) patients had regional cardiac sympathetic denervation compared with zero of nine control patients with a structurally normal heart (p = 0.029). Five patients underwent right ventricular radiofrequency ablation for ventricular tachycardia, and sympathetic denervation was adjacent to the ablation site in one of these patients.


CONCLUSIONS
Patients with ventricular tachycardia in the absence of coronary artery disease have abnormal cardiac sympathetic innervation detectable by cardiac sympathetic scintigraphy. The role of regional cardiac sympathetic denervation in arrhythmogenesis remains to be determined.
Mitrani
R D
RD
Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis 46202-4800.
Klein
L S
LS
Miles
W M
WM
Hackett
F K
FK
Burt
R W
RW
Wellman
H N
HN
Zipes
D P
DP
D019797:3-Iodobenzylguanidine; D000293:Adolescent; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D006328:Cardiac Catheterization; D009202:Cardiomyopathies / Q000150:complications* / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D017115:Catheter Ablation; D002648:Child; D004452:Echocardiography; D004594:Electrophysiology; D005080:Exercise Test; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications* / Q000000981:diagnostic imaging; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D013564:Sympathetic Nervous System; D017180:Tachycardia, Ventricular / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D013794:Thallium Radioisotopes; D019797:3-Iodobenzylguanidine