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WARNING OF CARDIAC ARREST DUE TO VENTRICULAR FIBRILLATION AND TACHYCARDIA
Saturday 24 June
WARNING OF CARDIAC ARREST DUE TO VENTRICULAR FIBRILLATION AND TACHYCARDIA
M. A. BENNETT General Hospital,
B. L. PENTECOST
Steelhouse Lane,
Birmingham B4 6NH
The character and duration of electroSummary cardiographic warning of cardiac arrest due to primary ventricular fibrillation and tachycardia was studied in 34 patients with myocardial infarction. Of 27 patients experiencing their first arrest after admission to the coronary care unit, 5 (19%) had no warning at all, 2 (7%) had warning for less than five minutes, and 20 had ventricular premature beats (V.P.B.S) for more than five minutes before arrest; the frequency of the V.P.B.S was usually less than five per minute. The degree of ventricular ectopic activity before cardiac arrest may be less than is generally realised. Among 7 patients readmitted to the unit after late cardiac arrest, recurrent ventricular tachyarrhythmia and V.P.B.S were common before each
1972
but with crepitations at the lung bases were included. Further patient-selection occurred because the recording system was capable of monitoring only 4 of the 5 patients in the unit at any one time. 6 patients who had primary cardiac arrest were lost to the study in this way. Results
After admission to the c.c.u., cardiac arrest with its preceding cardiac rhythm was recorded in 34 patients. 27 patients (group A) were direct admissions to the unit and had had no earlier cardiac arrest (patients 1-27, table l). 7 patients (group B) were studied who had previously been discharged from the C.c.u. but were readmitted after resuscitation for cardiac arrest on a general medical ward (patients TABLE I-WARNING OF CARDIAC ARREST IN GROUP A
episode. Introduction
IT is widely accepted that cardiac arrest due to ventricular tachyarrhythmias after myocardial infarction is usually preceded by warning ventricular premature beats (v.P.B.s) or short bursts of ventricular tachycardia, and this has led to the conclusion that prompt drug-treatment of such rhythm disturbances should substantially reduce the incidence of ventricular tachycardia and fibrillation.1-4 There are, however, few data on the duration and quality of the warning which precedes cardiac arrest. We have studied the degree of warning shown by patients in whom cardiac arrest developed within forty-eight hours of admission to a coronary care unit (c.c.u.). Cardiac arrest was usually a result of ventricular fibrillation, but was occasionally due to sustained rapid ventricular tachycardia which resulted in loss of consciousness. Patients and Methods 550
patients
with acute myocardial infarction
were
monitored for forty-eight hours; electromagnetic tape stored the continuously recorded rhythm. Our main interest was primary ventricular fibrillation; therefore patients with cardiogenic shock and cardiac failure were omitted from the study. Patients without severe dyspnoea 7765
* v.B.s.= ventricular extrasystoles. t v.T." ventricular tachycardia.
TABLE II-WARNING OF CARDIAC ARREST IN GROUP B
versely, recurrent late arrests are preceded by frequent ventricular extrasystoles and allow adequate time for antiarrhythmic drugs to be given. To be most effective in preventing ventricular tachycardia and fibrillation, antiarrhythmic drugs would need to be given to all patients on admission with acute infarction, by a route which permits high concentration to be attained rapidly. No drug regimen currently available has sufficient therapeutic value and low enough toxicity to justify its routine use. Requests for reprints should be addressed to B. L. P. REFERENCES
* V.B.S. = ventricular extrasystoles. t v. T. = ventricular tachycardia.
28-34, table 11). The late arrests in group B were thought to be related to extension of infarction, judged by serum-enzymes and electrocardiographic changes. In group A, 5 patients had cardiac arrest due to ventricular tachyarrhythmia without warning (patients 1-5, table i). Patients 6 and 7 arrested with less than five minutes’
warning, but of the remaining 20 patients
admitted directly to the unit (patients 8-27, table i) all had ventricular ectopic activity for at least five minutes before arrest. In 15 patients, however, the degree of warning was less than five V.P.B.S per minute, although the R-on-T phenomenon was seen in all
patients. The patients readmitted to the c.c.u. (group B, table n) all re-arrested within a matter of minutes rather than hours. All group B had frequent extrasystoles, and short bouts of ventricular tachycardia preceding the next episode of cardiac arrest were common.
Discussion
Patients who arrest from ventricular tachyarrhythmias in a c.c.u. are a highly selected group and cannot be said to reflect the natural history of cardiac arrest. We gave antiarrhythmic drugs when ventricular ectopic beats were frequent and when the R-on-T phenomenon was seen. Therefore, the group under study must have had a bias towards the inclusion of patients with little or no warning sign of arrest and a disproportionate number of patients with ectopic foci resistant to antiarrhythmic drugs. Similarly, bradycardia complicated by V.P.B.S was treated, so that this warning rhythm was not observed among those proceeding to cardiac arrest. Despite its limitations the study does indicate some points of therapeutic importance, particularly relevant to c.c.u. practice. The 7 patients who showed little or no warning all arrested in the ward within five hours of admission to the c.c.u.-6 within one hour. Similarly, a lack of warning was noted by Lawrie et al.in the study of a small group with primary ventricular fibrillation after infarction. A sizeable proportion of patients who arrest within the first hours after admission, therefore, do not have adequate warning to allow therapeutic intervention. Con-
1. Lown, B., Fakhro, A. M., Hood, W. B., Thorn, G. W. J. Am. med. Ass. 1967, 199, 188. 2. Mounsey, P. Am. J. Cardiol. 1967, 20, 475. 3. Thomas, M., Jewitt, D. E., Shillingford, J. P. Br. med. J. 1968, i, 787. 4. Pentecost, B. L., Mayne, N. M. C. ibid. p. 830. 5. Lawrie, D. M., Higgins, M. R., Godman, M. J., Oliver, M. F., Julian, D. G., Donald, K. W. Lancet, 1968, ii, 523.
LYMPHOPENIA AND CHANGE IN DISTRIBUTION OF HUMAN B AND T LYMPHOCYTES IN PERIPHERAL BLOOD INDUCED BY IRRADIATION FOR MAMMARY CARCINOMA
J. STJERNSWÄRD
M. JONDAL
F. VÁNKY
H. WIGZELL R. SEALY
Department of Tumour Biology, Karolinska Institutet, Karolinska Sjukhuset, Stockholm, Sweden; and Department of Radiotherapy, Groote Schuur Hospital, Cape Town, South Africa Irradiation for mammary carcinoma Summary frequently leads to a lymphopenia lastleast a year. at An analysis of the relative ing for
proportion of bone-marrow (B) and thymus (T) dependent lymphocytes in peripheral blood has been done in these patients. One surface marker characteristic for B lymphocytes (receptors for activated complement, EAC) and spontaneous rosette-forming capacity for sheep red blood-cells (E), a property of human T lymphocytes, have been investigated in peripheral-blood lymphocytes up to a year after radiotherapy. The ability of lymphocytes to respond to the stimulus of phytohæmagglutinin (P.H.A.) was also tested before and after irradiation was given in vivo. Thirty-four patients have been followed up by blood differentials over a year and the frequency of B and T cells analysed. A statistically significant lymphopenia was found 1 year after unilateral parastemal irradiation. Healthy controls had a mean of 32% EAC-binding lymphocytes (B cells) and 60% E-binding lymphocytes (T cells). After irradiation there was a statistically significant shift in the proportion of EAC and E binding lymphocytes, with a decrease of T lymphocytes to 45% and a relative increase of B cells to 52%. The ability of lymphocytes transform after in-vitro stimulation with P.H.A. was decreased in fifteen of nineteen patients tested. The data suggest that irradiation for mammary carcinoma
to
WARNING OF CARDIAC ARREST DUE TO VENTRICULAR FIBRILLATION AND TACHYCARDIA
M. A. BENNETT General Hospital,
B. L. PENTECOST
Steelhouse Lane,
Birmingham B4 6NH
The character and duration of electroSummary cardiographic warning of cardiac arrest due to primary ventricular fibrillation and tachycardia was studied in 34 patients with myocardial infarction. Of 27 patients experiencing their first arrest after admission to the coronary care unit, 5 (19%) had no warning at all, 2 (7%) had warning for less than five minutes, and 20 had ventricular premature beats (V.P.B.S) for more than five minutes before arrest; the frequency of the V.P.B.S was usually less than five per minute. The degree of ventricular ectopic activity before cardiac arrest may be less than is generally realised. Among 7 patients readmitted to the unit after late cardiac arrest, recurrent ventricular tachyarrhythmia and V.P.B.S were common before each
1972
but with crepitations at the lung bases were included. Further patient-selection occurred because the recording system was capable of monitoring only 4 of the 5 patients in the unit at any one time. 6 patients who had primary cardiac arrest were lost to the study in this way. Results
After admission to the c.c.u., cardiac arrest with its preceding cardiac rhythm was recorded in 34 patients. 27 patients (group A) were direct admissions to the unit and had had no earlier cardiac arrest (patients 1-27, table l). 7 patients (group B) were studied who had previously been discharged from the C.c.u. but were readmitted after resuscitation for cardiac arrest on a general medical ward (patients TABLE I-WARNING OF CARDIAC ARREST IN GROUP A
episode. Introduction
IT is widely accepted that cardiac arrest due to ventricular tachyarrhythmias after myocardial infarction is usually preceded by warning ventricular premature beats (v.P.B.s) or short bursts of ventricular tachycardia, and this has led to the conclusion that prompt drug-treatment of such rhythm disturbances should substantially reduce the incidence of ventricular tachycardia and fibrillation.1-4 There are, however, few data on the duration and quality of the warning which precedes cardiac arrest. We have studied the degree of warning shown by patients in whom cardiac arrest developed within forty-eight hours of admission to a coronary care unit (c.c.u.). Cardiac arrest was usually a result of ventricular fibrillation, but was occasionally due to sustained rapid ventricular tachycardia which resulted in loss of consciousness. Patients and Methods 550
patients
with acute myocardial infarction
were
monitored for forty-eight hours; electromagnetic tape stored the continuously recorded rhythm. Our main interest was primary ventricular fibrillation; therefore patients with cardiogenic shock and cardiac failure were omitted from the study. Patients without severe dyspnoea 7765
* v.B.s.= ventricular extrasystoles. t v.T." ventricular tachycardia.
TABLE II-WARNING OF CARDIAC ARREST IN GROUP B
versely, recurrent late arrests are preceded by frequent ventricular extrasystoles and allow adequate time for antiarrhythmic drugs to be given. To be most effective in preventing ventricular tachycardia and fibrillation, antiarrhythmic drugs would need to be given to all patients on admission with acute infarction, by a route which permits high concentration to be attained rapidly. No drug regimen currently available has sufficient therapeutic value and low enough toxicity to justify its routine use. Requests for reprints should be addressed to B. L. P. REFERENCES
* V.B.S. = ventricular extrasystoles. t v. T. = ventricular tachycardia.
28-34, table 11). The late arrests in group B were thought to be related to extension of infarction, judged by serum-enzymes and electrocardiographic changes. In group A, 5 patients had cardiac arrest due to ventricular tachyarrhythmia without warning (patients 1-5, table i). Patients 6 and 7 arrested with less than five minutes’
warning, but of the remaining 20 patients
admitted directly to the unit (patients 8-27, table i) all had ventricular ectopic activity for at least five minutes before arrest. In 15 patients, however, the degree of warning was less than five V.P.B.S per minute, although the R-on-T phenomenon was seen in all
patients. The patients readmitted to the c.c.u. (group B, table n) all re-arrested within a matter of minutes rather than hours. All group B had frequent extrasystoles, and short bouts of ventricular tachycardia preceding the next episode of cardiac arrest were common.
Discussion
Patients who arrest from ventricular tachyarrhythmias in a c.c.u. are a highly selected group and cannot be said to reflect the natural history of cardiac arrest. We gave antiarrhythmic drugs when ventricular ectopic beats were frequent and when the R-on-T phenomenon was seen. Therefore, the group under study must have had a bias towards the inclusion of patients with little or no warning sign of arrest and a disproportionate number of patients with ectopic foci resistant to antiarrhythmic drugs. Similarly, bradycardia complicated by V.P.B.S was treated, so that this warning rhythm was not observed among those proceeding to cardiac arrest. Despite its limitations the study does indicate some points of therapeutic importance, particularly relevant to c.c.u. practice. The 7 patients who showed little or no warning all arrested in the ward within five hours of admission to the c.c.u.-6 within one hour. Similarly, a lack of warning was noted by Lawrie et al.in the study of a small group with primary ventricular fibrillation after infarction. A sizeable proportion of patients who arrest within the first hours after admission, therefore, do not have adequate warning to allow therapeutic intervention. Con-
1. Lown, B., Fakhro, A. M., Hood, W. B., Thorn, G. W. J. Am. med. Ass. 1967, 199, 188. 2. Mounsey, P. Am. J. Cardiol. 1967, 20, 475. 3. Thomas, M., Jewitt, D. E., Shillingford, J. P. Br. med. J. 1968, i, 787. 4. Pentecost, B. L., Mayne, N. M. C. ibid. p. 830. 5. Lawrie, D. M., Higgins, M. R., Godman, M. J., Oliver, M. F., Julian, D. G., Donald, K. W. Lancet, 1968, ii, 523.
LYMPHOPENIA AND CHANGE IN DISTRIBUTION OF HUMAN B AND T LYMPHOCYTES IN PERIPHERAL BLOOD INDUCED BY IRRADIATION FOR MAMMARY CARCINOMA
J. STJERNSWÄRD
M. JONDAL
F. VÁNKY
H. WIGZELL R. SEALY
Department of Tumour Biology, Karolinska Institutet, Karolinska Sjukhuset, Stockholm, Sweden; and Department of Radiotherapy, Groote Schuur Hospital, Cape Town, South Africa Irradiation for mammary carcinoma Summary frequently leads to a lymphopenia lastleast a year. at An analysis of the relative ing for
proportion of bone-marrow (B) and thymus (T) dependent lymphocytes in peripheral blood has been done in these patients. One surface marker characteristic for B lymphocytes (receptors for activated complement, EAC) and spontaneous rosette-forming capacity for sheep red blood-cells (E), a property of human T lymphocytes, have been investigated in peripheral-blood lymphocytes up to a year after radiotherapy. The ability of lymphocytes to respond to the stimulus of phytohæmagglutinin (P.H.A.) was also tested before and after irradiation was given in vivo. Thirty-four patients have been followed up by blood differentials over a year and the frequency of B and T cells analysed. A statistically significant lymphopenia was found 1 year after unilateral parastemal irradiation. Healthy controls had a mean of 32% EAC-binding lymphocytes (B cells) and 60% E-binding lymphocytes (T cells). After irradiation there was a statistically significant shift in the proportion of EAC and E binding lymphocytes, with a decrease of T lymphocytes to 45% and a relative increase of B cells to 52%. The ability of lymphocytes transform after in-vitro stimulation with P.H.A. was decreased in fifteen of nineteen patients tested. The data suggest that irradiation for mammary carcinoma
to