RT Journal Article SR Electronic T1 Treatment of hypertrophic obstructive cardiomyopathy with verapamil JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 714 OP 714 DO 10.1136/hrt.43.6.714 VO 43 IS 6 A1 I L Geft A1 M M Zion A1 M Kaltenbach A1 R Hopf YR 1980 UL http://heart.bmj.com/content/43/6/714.abstract AB