Læknablaðið : fylgirit - 01.06.1982, Qupperneq 26

14
CARDIAC ARRHYTHÍ-IIAS IN HYPERTROPHIC CARDIOMYOPT'THY.
Ingvar Bjamason, Thordur Hardarson, Stefan Jonsson, Reykjavik
City Hospital, Itedical Departinent.
Patients with hypertrophic cardioiryopathy (HC) frequently
die suddenly and unexpectedly, presumably from cardiac
arrhythinias. We studied by 24-hour Holter ambulatory monitor-
ing 51 close relatives of eight patients with HC v/ho came to
autopsy in Iceland during the years 1966 to 1577. A total of
11 patients with the disease were autopsied during these years.
Twenty two of the relatives had HC as defined by an echocardio-
graphic demonstration of inordinate septal thickening ( 1.3cm)
Nineteen of them were asymptomatic, tv.o were in New York Heart
Association Class III and one in Class IV. Twenty nine
relatives and 40 normal subjects served as control groups.
All were without symptoms.Seven patients had >. 50 supraventric-
ular extrasystoles per day, but only one subject in the group
of relatives and one in the control group. Eight patients
with hypertrophic cardiomyopathy had supraventricular arrhythm-
ias. Three patients with hypertrophic cardiomyopathy had runs
of ventricular tachycardia but none in the two other groups.
TWo patients with hypertrophic cardiomyopathy had coupled
ventricular ectopic beats, one in the normal control group.
Nine patients with hypertrophic cardioiryopathy had multiform
ventricular ectopics, one in the normal group. Twelve patients
with hypeirtrophic cardiomyopathy had more than 10 ventricular
extrasystoles per day as conpared with four in the control
group and two in the group of relatives.
This study shows: 1) A strong correlation between in-
ordinate septal thickening and arrhythmia in a (mostly)
asymptomatic group of relatives of patients with HC, suggesting
that they do also suffer from HC. 2) That many relatives of
patients with HC have an unexpectedly hich incidence of
arrhythmias, perhaps putting them at risk of dying suddenly.
Relatives of patients with HC should be studied by echocardio-
graphy and subsequently Holter monitoring if a thickened inter-
ventricular septum is demonstrated.