Catecholaminergic polymorphic ventricular tachycardia: electrocardiographic characteristics and optimal therapeutic strategies to prevent sudden death.
OBJECTIVE
To investigate the clinical outcome, ECG characteristics, and optimal treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), a malignant and rare ventricular tachycardia.


METHODS
Questionnaire responses and ECGs of 29 patients with CPVT were evaluated. Mean (SD) age of onset was 10.3 (6.1) years.


RESULTS
The initial CPVT manifestations were syncope (79%), cardiac arrest (7%), and a family history (14%). ECGs showed sinus bradycardia and a normal QTc. Mean heart rate during CPVT was 192 (30) beats/min. Most cases were non-sustained (72%), but 21% were sustained and 7% were associated with ventricular fibrillation. The morphology of CPVT was polymorphic (62%), polymorphic and bidirectional (21%), bidirectional (10%), or polymorphic with ventricular fibrillation (7%). There was 100% inducement of CPVT by exercise, 75% by catecholamine infusion, and none by programmed stimulation. No late potential was recorded. Onset was in the right ventricular outflow tract in more than half the cases. During a follow up of 6.8 (4.9) years, sudden death occurred in 24% of the patients, 7% of whom had anoxic brain damage. Autosomal dominant inheritance was seen in 8% of the patients' families. beta Blockers completely controlled CPVT in only 31% of cases. Calcium antagonists partially suppressed CPVT in autosomal dominant cases.


CONCLUSIONS
CPVT may arise in certain distinct areas but the prognosis is poor. The onset of CPVT may be an indication for an implanted cardioverter-defibrillator.
Sumitomo
N
N
Department of Paediatrics, Nihon University School of Medicine, Itabashi, Tokyo, Japan. jt9n-smtm@asahi-net.or.jp
Harada
K
K
Nagashima
M
M
Yasuda
T
T
Nakamura
Y
Y
Aragaki
Y
Y
Saito
A
A
Kurosaki
K
K
Jouo
K
K
Koujiro
M
M
Konishi
S
S
Matsuoka
S
S
Oono
T
T
Hayakawa
S
S
Miura
M
M
Ushinohama
H
H
Shibata
T
T
Niimura
I
I
D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D002395:Catecholamines / Q000235:genetics*; D017115:Catheter Ablation / Q000379:methods; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome; D014700:Verapamil / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002395:Catecholamines; D014700:Verapamil