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Detection of myocardial ischaemia in ambulatory patients with daily angina
ABSTRACTS
WEDNESDA Y, MARCH 14, 1979 PM SUDDEN DEATH AND AMBULATORY MONITORING 2:00-5:00
SIGNIFICANCE OF "SLOW" VENTRICULAR TACHYCARDIAAND "SLOW" VENTRICULAR COUPLETS DURING AMBULATORY ECG MONITORING. Harry A. Hai, M~D., Maxine R. Nelson, R.N,, Terry L. Ostrowski, M.D.; Arrhythmia Control Unit; Northwestern University Medical Center; Chicago, Illinois.
AMBULATORY ELECTROCARDIOGRAPHY: WHAT iS NORMAL? John B. Kostis, MD, FACC; Abel E. Moreyra, MD; N. N a t a r a jan, M I), FACC; S. Gotzoyannis, MD; Maryhelen Hosler, R N ; Katherine McCrone, RN; and Peter T. Kuo, MD, FACC.
"Slow" ventricular tachycardia (VT) may be defined as VT at a rate below i00 per minute. This arrhythmia is generally believed to carry a less malignant prognosis than rapid VT when observed in a patient with recent acute myocardial infarction. The prognostic significance of "slow" ventricular tachycardia, observed during ambulatory monitoring, however, is unknown. Similarly, the significance of "slow" ventricular couplets is unknown when observed during ambulatory monitoring. To determine the frequency and associations of these "slow" repetitive ventricular arrhythmias, we reviewed 475 consecutive ambulatory monitoring tapes. "Slow" VT was observed in 12 of the 475 tapes. Of these, ii (92%) also showed rapid ventricular couplets, 6 (50%) also showed rapid VT, and one (8.3%) had ventricular fibrillation on the Same tape. The only exception in this group was the tape from a young woman with congenital heart block who had "slow" VT but no rapid ventricular arrhythmia. "Slow" ventricular couplets were observed in 33 of the 475 tapes. Of these, 29 (88%) demonstrated the presence of one or more rapid ventricular couplets at some time during the same 24 hour period, and I0 showed rapid VT in addition. The high association of repetitive "slow" ventricular arrhythmias with rapid ventricular arrhythmias appears to indicate that the former generally carry implications similar to the latter when Observed during ambulatory ECG monitoring.
Twenty-four hour ambulatory electrocardiography (AE) was performed on .!00 subjects (age 16 to 68, mean 49; 55 men, 45 women) with normal hearts (N) verified by extensive clinical, noninvasive (including treadmill exercise and echocardiography) and invasive (including right and left heart cath and coronary arteri0graphy ) testing and on 40__O0apparently normal (AN) volunteers (age 16 to 69, mean 48; 254 men, 146 women). In N, heart rate ranged from 37 to 180, showed dlurual variation with maximum around I0 am and minimum around ~ am varied markedly withln+each hour of the day (by 27 - 7.2 beats) and night (19 - 6.1). Conduction defect o r bradyarrhythmlas other than sinus bradycardia were not observed. Forty-six N had at least one premature ventricular contraction (PVC) but only 20 N had more than i0 and only 5 N had more than 100 PVC per 24 hours. In the hour with most PVCs, 12 N had more than 5 PVC per hour. In AN a higher (P<0.05) incidence of PVC (59 of 400 had more than 100 PVC per 24 hours) and a positive associatlon with age (P0.1) effect of age, sex, blood pressure, cholesterol, triglyceride, Na+, K+ or Ca++ on PVC was noted. A correlation of PVC and heart rate (r=0.61) was seen in N. Conclusions: i) i00 PVC/24 hours or 5 PVC/hour may be used as the limits of normal in AE 2) the higher incidence of P V C in AN and their correlation with age, sex and blood pressure may be due to u n d e t e c t e d CAD.
DETECTION OF MYOCARDIAL ISCHAEMIA IN AMBULATORY PATIENTS WITH DAILY ANGINA. M a r t i n Eves, MA; Andrew Selwyn, MB; Kim Fox, MB; David Oakley, MB; John Shillingford, MD, FACC; Hammer smith Hospital, London. 24 hour ambulatory monitoring using an Oxford ECG recorder and 16 point praecordial mapping after exercise has been used to study 100 patients with daily angina. All showed pathological ST depression after exercise though in only 45% was the maximum ST depression at the conventional positi0n VS. In a further 20% V5 was on the edge of the praecordial area and showed less severe depression than the central area. The exploring electrode was placed on the praecordiai position showing the earliest and maximum changes in the ST segment d u r i n g the exercise test. A mean of 14Z3.0 episodes of ST depression were detected in each patient. Only 16Z4.O% of these episodes were a c c o m p a n i e d b y reported chest pain. Mere episodes occurred between 4 and 6am than during any other 2 hour period during the night (P= .01). In those patients in whom V5 was on the edge of the exercise induced area of ischaemia exploring electrodes ~ were placed on V5 and the central position showing maximum ST changes. These simultaneous 24 hour recordings Showed that V5 detected on 14±4.0% of the episodes of ST depression recorded at the central position. In conclusion more information is obtained about myocardial ischaemia when the exploring electrode is placed on the praecordial position showing the earliest and maximum ST segment depression during exercise, Objective information is provided about the frequency, timing and severity of myocardial ischaemia during the daily activities of patients with ischaemi9 heart d i s e a s e .
420
February 1979
The American Journal of CARDIOLOGY
.EXERCISE ELECTROCARDIOG~PHIC AND 48 HOUR AMBULATORY ELECTROCARDIOGRAPHIC MONITOR ASSESSMENT OF ARRHYTHMIA ON AND OFF BETA BLOCKER THERAPY IN HYPERTROPHIC CARDIOMYOPATHY William J. McKenna, MD; Soondree Chetty, MRCP; Celia M. Oakley, FRCP, FACC; and John F. Goodwin, FRCP, FACC, Royal Postgraduate Medical School, London, England. Submaximal treadmill exercise electrocardiography (ECG) and 48 hour continuous ambulatory ECG monitoring of 27 patients (pts) with hypertrophic cardiomyopathy both on and off B Blocker therapy was performed. During 48 hour ambulatory ECG monitoring on treatment: 15 pts had frequent (~ iO/IOOO QRS) ventricularextra systoles (VES) 7 o f the i5 were multiform and 5 pts had occasional (< iO/iOOO QRS) VES; ii pts had frequent atrial extra systoles (AES) and 6 pts had occasional AES; 6 pts had occasional supraventricular tachycardia (SVT), 2 had frequent SVT and 3 pts had ventricular tachycardia (VT > 3 VES in a row), During 48 hour ambulatory ECG monitoring off treatment: 15 p t s h a d frequent VES, 6 of the 15 were multiform and 7 pts had occasional VES; 5 pts had frequent A E S a n d 9 pts occasionai AES; 6 pts had occasional SVT, 3 pts frequent SVT and 4 pts had VT. During treadmill exercise ECG on treatment 14 pts had occasional VES and off treatment 16 pts had occasional VES and 2 pts frequent VES. On exercise testing no pt had AES, SVT or VT. Ambulatory ECG monitoring showed that 16 of 27 pts with hypertrophic cardiomyopathy had frequent serious arrhythmias which were not detected during exercise ECG testing. As occult dysrhythmia may be the cause of sudden death in hypertrophic cardiomyopathy it is important to detect these patients because specific antiarrhythmia treatment may improve prognosis. Tn this study, however, B blockers therapy had no significant effect on the frequency of the dysrhythmias.
Volume 43
WEDNESDA Y, MARCH 14, 1979 PM SUDDEN DEATH AND AMBULATORY MONITORING 2:00-5:00
SIGNIFICANCE OF "SLOW" VENTRICULAR TACHYCARDIAAND "SLOW" VENTRICULAR COUPLETS DURING AMBULATORY ECG MONITORING. Harry A. Hai, M~D., Maxine R. Nelson, R.N,, Terry L. Ostrowski, M.D.; Arrhythmia Control Unit; Northwestern University Medical Center; Chicago, Illinois.
AMBULATORY ELECTROCARDIOGRAPHY: WHAT iS NORMAL? John B. Kostis, MD, FACC; Abel E. Moreyra, MD; N. N a t a r a jan, M I), FACC; S. Gotzoyannis, MD; Maryhelen Hosler, R N ; Katherine McCrone, RN; and Peter T. Kuo, MD, FACC.
"Slow" ventricular tachycardia (VT) may be defined as VT at a rate below i00 per minute. This arrhythmia is generally believed to carry a less malignant prognosis than rapid VT when observed in a patient with recent acute myocardial infarction. The prognostic significance of "slow" ventricular tachycardia, observed during ambulatory monitoring, however, is unknown. Similarly, the significance of "slow" ventricular couplets is unknown when observed during ambulatory monitoring. To determine the frequency and associations of these "slow" repetitive ventricular arrhythmias, we reviewed 475 consecutive ambulatory monitoring tapes. "Slow" VT was observed in 12 of the 475 tapes. Of these, ii (92%) also showed rapid ventricular couplets, 6 (50%) also showed rapid VT, and one (8.3%) had ventricular fibrillation on the Same tape. The only exception in this group was the tape from a young woman with congenital heart block who had "slow" VT but no rapid ventricular arrhythmia. "Slow" ventricular couplets were observed in 33 of the 475 tapes. Of these, 29 (88%) demonstrated the presence of one or more rapid ventricular couplets at some time during the same 24 hour period, and I0 showed rapid VT in addition. The high association of repetitive "slow" ventricular arrhythmias with rapid ventricular arrhythmias appears to indicate that the former generally carry implications similar to the latter when Observed during ambulatory ECG monitoring.
Twenty-four hour ambulatory electrocardiography (AE) was performed on .!00 subjects (age 16 to 68, mean 49; 55 men, 45 women) with normal hearts (N) verified by extensive clinical, noninvasive (including treadmill exercise and echocardiography) and invasive (including right and left heart cath and coronary arteri0graphy ) testing and on 40__O0apparently normal (AN) volunteers (age 16 to 69, mean 48; 254 men, 146 women). In N, heart rate ranged from 37 to 180, showed dlurual variation with maximum around I0 am and minimum around ~ am varied markedly withln+each hour of the day (by 27 - 7.2 beats) and night (19 - 6.1). Conduction defect o r bradyarrhythmlas other than sinus bradycardia were not observed. Forty-six N had at least one premature ventricular contraction (PVC) but only 20 N had more than i0 and only 5 N had more than 100 PVC per 24 hours. In the hour with most PVCs, 12 N had more than 5 PVC per hour. In AN a higher (P<0.05) incidence of PVC (59 of 400 had more than 100 PVC per 24 hours) and a positive associatlon with age (P
DETECTION OF MYOCARDIAL ISCHAEMIA IN AMBULATORY PATIENTS WITH DAILY ANGINA. M a r t i n Eves, MA; Andrew Selwyn, MB; Kim Fox, MB; David Oakley, MB; John Shillingford, MD, FACC; Hammer smith Hospital, London. 24 hour ambulatory monitoring using an Oxford ECG recorder and 16 point praecordial mapping after exercise has been used to study 100 patients with daily angina. All showed pathological ST depression after exercise though in only 45% was the maximum ST depression at the conventional positi0n VS. In a further 20% V5 was on the edge of the praecordial area and showed less severe depression than the central area. The exploring electrode was placed on the praecordiai position showing the earliest and maximum changes in the ST segment d u r i n g the exercise test. A mean of 14Z3.0 episodes of ST depression were detected in each patient. Only 16Z4.O% of these episodes were a c c o m p a n i e d b y reported chest pain. Mere episodes occurred between 4 and 6am than during any other 2 hour period during the night (P= .01). In those patients in whom V5 was on the edge of the exercise induced area of ischaemia exploring electrodes ~ were placed on V5 and the central position showing maximum ST changes. These simultaneous 24 hour recordings Showed that V5 detected on 14±4.0% of the episodes of ST depression recorded at the central position. In conclusion more information is obtained about myocardial ischaemia when the exploring electrode is placed on the praecordial position showing the earliest and maximum ST segment depression during exercise, Objective information is provided about the frequency, timing and severity of myocardial ischaemia during the daily activities of patients with ischaemi9 heart d i s e a s e .
420
February 1979
The American Journal of CARDIOLOGY
.EXERCISE ELECTROCARDIOG~PHIC AND 48 HOUR AMBULATORY ELECTROCARDIOGRAPHIC MONITOR ASSESSMENT OF ARRHYTHMIA ON AND OFF BETA BLOCKER THERAPY IN HYPERTROPHIC CARDIOMYOPATHY William J. McKenna, MD; Soondree Chetty, MRCP; Celia M. Oakley, FRCP, FACC; and John F. Goodwin, FRCP, FACC, Royal Postgraduate Medical School, London, England. Submaximal treadmill exercise electrocardiography (ECG) and 48 hour continuous ambulatory ECG monitoring of 27 patients (pts) with hypertrophic cardiomyopathy both on and off B Blocker therapy was performed. During 48 hour ambulatory ECG monitoring on treatment: 15 pts had frequent (~ iO/IOOO QRS) ventricularextra systoles (VES) 7 o f the i5 were multiform and 5 pts had occasional (< iO/iOOO QRS) VES; ii pts had frequent atrial extra systoles (AES) and 6 pts had occasional AES; 6 pts had occasional supraventricular tachycardia (SVT), 2 had frequent SVT and 3 pts had ventricular tachycardia (VT > 3 VES in a row), During 48 hour ambulatory ECG monitoring off treatment: 15 p t s h a d frequent VES, 6 of the 15 were multiform and 7 pts had occasional VES; 5 pts had frequent A E S a n d 9 pts occasionai AES; 6 pts had occasional SVT, 3 pts frequent SVT and 4 pts had VT. During treadmill exercise ECG on treatment 14 pts had occasional VES and off treatment 16 pts had occasional VES and 2 pts frequent VES. On exercise testing no pt had AES, SVT or VT. Ambulatory ECG monitoring showed that 16 of 27 pts with hypertrophic cardiomyopathy had frequent serious arrhythmias which were not detected during exercise ECG testing. As occult dysrhythmia may be the cause of sudden death in hypertrophic cardiomyopathy it is important to detect these patients because specific antiarrhythmia treatment may improve prognosis. Tn this study, however, B blockers therapy had no significant effect on the frequency of the dysrhythmias.
Volume 43