Br Heart J: first published as 10.1136/hrt.28.3.426 on 1 May 1966. Downloaded from

Brit. Heart J7., 1966, 28, 426.

Proceedings of The British Cardiac Society

THE AUTUMN MEETING of the British Cardiac Society COMPUTERS IN CARDIOVASCULAR INVESTIGATION was held at the Royal College of Physicians on Friday, By S. H. Taylor, A. Macdonald, R. Sapru November 26, 1965. The President, SHIRLEY SMITH, (last two introduced), and K. W. Donald took the Chair at 9.0 a.m. during Private Business before handing over to the Chairman, WILLIAM EVANS. 175 The facility with which circulatory measurements members and 75 visitors were present. may be made is imposing considerable restriction on the The second Thomas Lewis Lecture was given at design of circulatory investigations due to the problems 5.0 p.m. by Dr. Bernard Lown on "Cardioversion of of measurement of the data involved. A study was, ". therefore, designed to explore the practical feasibility of analysing cardiovascular measurements with the aid of a transducer-computer link and digital computer. PRIVATE BUSINESS In addition the accuracy of the three small proprietary 1. The Minutes of the Annual General Meeting, cardiac output computers currently available has been having been published in the Journal (1965, 27, assessed and the problems associated with their opera- 942), were taken as read and confirmed. tion evaluated. 2. The Treasurer reported that cash in the current The combination of these small on-line cardiac account stood at £1,206, deposit account at £100, output monitors in association with off-line data storage and investments at £529. and analysis by digital computation offers important £50 had been paid to the Society of Cardio- advantages not only in routine or research cardiovascular logical Technicians, as arranged, in July. investigation but also in the monitoring of patients The Congress Fund held £12 14s. 9d. in the acutely ill with circulatory disorders. current account, £400 in the deposit account, and http://heart.bmj.com/ investments still stood at £732 18s. 4d. MEASUREMENT OF RIGHT VENTRICULAR £200 was ear-marked for expenses of members END-SYSTOLIC AND END-DIASTOLIC VOLUMES attending the World Congress in New Delhi in BY A THERMODILUTION TECHNIQUE 1966. By R. Balcon (introduced by S. Oram) The Thomas Lewis Lecture Fund held This communication is a preliminary account of £18 7s. 5d. in current account with investments at £1,173 1Os. 2d. experience with a new method of measuring ventricular 3. The Secretary reported that the Annual General volumes.

The history and theory of indicator dilution methods on September 24, 2021 by guest. Protected copyright. Meeting would be held on April 14, 1966 in for the assessment of ventricular volumes is reviewed. Cambridge under the Chairmanship of Cole. The application of a thermodilution technique is des- Milstein will be the Local Secretary. cribed in the investigation of various cardiac abnorm- 4. The V World Congress of is to be held alities. An analysis of the findings obtained in these in New Delhi from October 30 to November 5, patients is given, and an attempt made to correlate the 1966. changes with other parameters of ventricular function 5. The Autumn Meeting of the Society will be held at such as end-diastolic pressure and stroke output. the Royal College of Physicians on December 1-2, An account is given of some of the difficulties en- 1966. The Dinner will be held at the end of the countered in the application of this technique and some first day. solutions are 6. The Annual General Meeting in 1967 will be held in possible suggested. Belfast on May 18. 7. RIGHT VENTRICULAR VOLUMES ESTIMATED The European Congress of Cardiology will be held BY THE THERMODILUTION TECHNIQUE in Athens in 1968. AFTER RADICAL CORRECTION OF THE After the Scientific Meeting the Society dined together TETRALOGY OF FALLOT at the Royal College of Physcians with Shirley Smith in the Chair. Shirley Smith proposed the health of the By Maylene Wong (introduced) and Michael Dulake guests who included Sir Charles Dodds, Dr. and Mrs. The thermodilution technique for measuring ven- Bernard Lown, and H. G. Lazell, Esq. William Evans tricular volume was applied to subjects in whom the replied. tetralogy of Fallot had been radically corrected. 426 Br Heart J: first published as 10.1136/hrt.28.3.426 on 1 May 1966. Downloaded from

Proceedings of The British Cardiac Society 427 A conventional diagnostic right heart catheterization ELECTIVE CIRCULATORY ARREST BY was performed to exclude any shunt. In 9 such patients ARTIFICIAL PACEMAKER a special catheter was introduced, a rapid responding By J. M. Small, S. C. F. Stephenson, T. V. Campkin, thermister bead at its tip being placed in the pulmonary D. J. S. McIlveen (all introduced), and P. H. Davison artery and the side-hole in the right . Pressures and samples could be obtained through the latter, and During operations on 12 patients with cerebral an- 1-2 ml. of cold saline were injected to obtain a staircase eurysm, the circulation was profoundly reduced or ar- exponential temperature curve from the thermister in the rested by an electrode catheter in the right ventricle, pulmonary artery. Cardiac output was obtained by the which was used to pace the heart at rates up to 240 a Cardio-green dye dilution technique before and after a minute. Electrocardiographic, aortic, and right atrial series of thermodilution curves at rest and under the pressures were monitored. The patients were cooled to influence of infused isoprenaline. 31-32° C. Under these conditions the cardiac output and Forward stroke volume (FSV) was obtained from the systemic blood pressure were very sensitive to the pacing cardiac output. rate. Above 120 a minute there was reduction of both. At rates of 160 or more, systolic pressures below 30 mm. T +1+ 1 Hg were maintained for periods up to 15 minutes with- volume (EDV) = FSV/1 End-diastolic T-Tn out loss of control of cardiac rhythm. With faster where Tn+1 and Tn are differences between the rates and systolic pressures below 20 mm. Hg, ventri- baseline pulmonary artery temperature and those at cular usually occurred within 1 to 2 minutes. beats Tn + 1 and Tn on the thermodilution curve. Reversion by D.C. shock and extemal cardiac massage was then used. Elective arrest with ventricular fibril- FSV/EDV = 1 T+ 1. lation has been maintained for periods up to 64 minutes. There has been no morbidity or mortality to date. The End-systolic volume = EDV- FSV. method offers a useful altemative to inflow occlusion. The data were shown and the advantages and limita- tions of the technique discussed. MYOCARDIAL THRESHOLD AND IMPEDANCE IN COMPLETE : METHODS FOR ASSESSING EXPERIMENTAL RESULTS AND CLINICAL FUNCTION AND MALFUNCTION APPLICATION OF PAIRED STIMULATION PACEMAKER OF THE HEART By R. D. Judge, T. A. Preston, D. L. Bowers, and J. D. Morris (all introduced by E. Sowton) By Edgar Sowton, Leon Resnekov, Peter Lord, and two introduced) Analysis of 120 pacemaker implants disclosed that the John Norman (the last http://heart.bmj.com/ major causes for failure were (1) lead fracture, (2) The application of closely coupled pairs of electrical battery failure, (3) exit block. Fortunately, component stimuli to the heart provides the most potent inotropic failure has not been a problem. This experience intervention known at present, and also offers a possible emphasized the need for developing indirect methods of method of controlling intractable arrhythmias. The monitoring myocardial threshold and impedance to aid first stimulus of each pair provokes a ventricular con- in exactly identifying malfunction and anticipating traction, but the second stimulus is timed to cause an failure before they manifested themselves clinically. electrical depolarization without any appreciable mech- The circuit design of one unit has made possible the anical activity, so that there are 2 electrical events for development of a simple and safe method of determining each ventricular contraction. (1) threshold, (2) myocardial resistance, (3) electrode on September 24, 2021 by guest. Protected copyright. In 13 dogs, paired stimulation invariably slowed the capacitance, (4) battery level. All parameter measure- heart below its sinus rate, and also slowed ments are made extemally (without surgery) by ana- of sinus, ventricular, or supraventricular origin; the lysing various electromagnetic signals emitted by the maximum slowing was by just under 50 per cent. pacemaker. Preliminary studies in dogs have shown Where the had resulted in a low cardiac the following: that the methods are safe; that it is possible output, paired stimulation restored aortic flow to normal. to predict energy values from pulse signal analysis; that In dogs with severe paired stimulation increases in rate cause increases in threshold. As resulted in a fall in LV end-diastolic pressure, an increase expected, threshold proved to be a function of total in LV DP/DT and LV peak systolic pressure, and a pulse energy. Using calibrated pacemakers, it was dramatic increase in aortic blood flow. The effects possible to measure myocardial resistance and electrode were reversible and highly repeatable, and stimulation at capacitance following human implantation. In a the same rate with single stimuli produced no beneficial series of 20 patients, capacitance varied insignificantly, effects. while resistance increased gradually during the immedi- The technique has been applied clinically in 3 patients ate post-operative period and then became stable. with severe intractable arrhythmias. In one case Myocardial impedance did not always vary directly with clinical and hmmodynamic benefit was obtained for 48 threshold changes. These studies not only demonstrate hours. Since the second stimulus of the pair falls near a simple, practical method of monitoring pacemaker the vulnerable period, there is a risk ofinducing ventricu- function, but also promise a means of studying the lar fibrillation, and this occurred in 1 patient. electrophysiological effects of cardiac drugs in the future. Br Heart J: first published as 10.1136/hrt.28.3.426 on 1 May 1966. Downloaded from

428 Proceedings of The British Cardiac Society ATRIAL FUNCTION FOLLOWING CARDIOVERSION SELECTIVE CINEFLUOROSCOPIC STUDIES OF PULMONARY CIRCULATORY DISORDERS* By W. F. W. E. Logan, D. J. Rowlands (both introduced), and G. Howitt By M. J. Raphael (introduced) and R. E. Steiner Left and right atrial pressure pulses have been recorded We report some results in our investigation of patho- from patients with of various oetiologies. logical pulmonary circulation in heart disease using the In some instances, simultaneous ventricular traces Chrispin and Steiner (1964) technique of selective have been recorded. Similar records have been taken pulmonary cine-angiography. Out of 60 patients immediately after D.C. conversion to . studied, we have selected the examinations illustrating Comparison of the records taken before and after the the changes in circulation in 8 patients with varying rhythm change has revealed a disparity between the degrees of pulmonary hypertension secondary to effect of cardioversion on the electrical activity and its acquired and in 6 patients with effect upon the mechanical activity of the atria. In all intracardiac shunts of varying sizes. cases, normal atrial excitation was restored, as evidenced In patients with raised left atrial pressures and vary- by the development of clearly discernible P waves with ing degrees of pulmonary hypertension, the reduced a normal P-R interval and with a regular ventricular lower lobe blood flow is manifested by impaired onward rate. In most cases these changes in the electrocardio- movement of the contrast medium with each heart graph have been accompanied by the development of beat and delayed appearance time of contrast in the 'a' waves in the right atrial pressure trace. However, pulmonary veins. in a very significant proportion of cases of rheumatic In patients with small intracardiac shunts and vessels valve disease no such 'a' waves were developed in the ofnormal size, the angiographic studies follow the normal left atrial pressure trace. The possible mechanism and pattern. When the shunt is large and associated with significance of these findings are discussed. distended pulmonary vessels, the onward movement of contrast medium in the pulmonary artery with each heart beat is accentuated. Unless the shunt is very NON-RHEUMATIC MITRAL INCOMPETENCE large, the period of diastolic stasis of contrast medium is maintained as in normal patients. This suggests that By E. B. Raftery (introduced), C. M. Oakley, and pulsatile arterial flow is still maintained even in the J. F. Goodwin presence of large shunts. Contrast very rapidly reaches Non-rheumatic causes of mitral incompetence include the enlarged veins and fails to show pulsatile fluctua- left atrial tumour, subannular ventricular aneurysm, and tions in density, thus suggesting absence of pulsatile , as well as endocardial cushion defects venous flow. and other congenital anomalies involving the mitral The disappearance of pulsatile flow in the pulmonary http://heart.bmj.com/ valve. Recently the clinical syndrome associated with veins in patients with large shunts is surprising, in view acquired disease of mitral chorde or papillary muscles of the accentuated pulmonary arterial pulsation. This has become recognized, and in the past two years 15 paradox might be explained by the excessive venous such patients have been seen at Hammersmith Hospital. distension producing a volume damping effect. The clinical features included sudden onset of dys- pnoea or pulmonary cedema with development of an EXPERIENCE WITH BYPASS SURGERY IN apical systolic murmur conducted to the base and CORONARY ARTERIAL DISEASE COMPLICATING mimicking . Sinus rhythm was the rule

AORTIC VALVAR DISEASE on September 24, 2021 by guest. Protected copyright. and the heart tended to be only slightly enlarged. The left atrial pressure pulse characteristically showed giant By Dennis Boyle (introduced), Lawson McDonald, 'v waves which reflected torrential retrograde flow into a Leon Resnekov, and Donald Ross normal-sized left . In 66 patients with aortic who It was not possible to make a distinction between valvar disease, under- went bypass surgery, 20 were found to have ruptured chordle and papillary muscle dysfunction on con- clinical or angiographic grounds, but evidence of comitant coronary arterial disease, as evidenced by subendocardial cardiac infarction indicated failure of macroscopical abnormalities of the coronary arteries papillary muscle function to be the cause in four patients. and infarctions of the left ventricular wall. The mor- Two patients with ruptured chordae had recently had tality rate, following surgery, was similar in patients bacterial , and one patient had papillary who had coronary arterial disease and in those who had muscle invasion by sarcoid granuloma. The ttiology not. Symptoms, clinical signs, and electrocardiographic was unknown in the others, and a familial incidence findings were unhelpful in the precise diagnosis of addi- was not found. tional coronary arterial disease, and will be discussed in relation to radiographic findings and other special As pulmonary oedema may result from overfilling of an undiluted pulmonary venous reservoir rather than from investigations. With aortic valvar disease, in which surgery is indicated, the presence of additional left ventricular failure, these patients can present a coronary particularly urgent but low risk surgical problem. arterial disease is not considered to be a contra- Four patients were operated upon and the indication to operation. successfully replaced. * To be published in full in a future issue of this Journal. Br Heart J: first published as 10.1136/hrt.28.3.426 on 1 May 1966. Downloaded from

Proceedings of The British Cardiac Society 429 FATE OF THE HUMAN HOMOGRAFT stenosis. This communication outlines findings in 4 By R. Hudson such patients. [Published in full in Brit. Heart_J., 1966, 28, 291.] The facial characteristics are described and illustrated. The facile good-humoured personality with low intelli- OBSTRUCTED TOTAL ANOMALOUS PULMONARY VENOUS gence quotient is emphasized. The clinical findings are DRAINAGE listed, stressing inequality of radial pulses and blood By Jane Somerville and Alan Chrispin (introduced) pressure, the localization of the systolic thrill and mur- mur, and the absence of ejection click or diastolic mur- In a consecutive series of 80 patients with total anomal- mur. The radiological features are illustrated, particu- ous pulmonary venous drainage, 18 (22%) were found larly the absence of post-stenotic dilatation of the aorta. to have obstruction of the common pulmonary venous The electrocardiographic findings are noted, especially channel; patients with cor triatriatum were excluded. the occurrence of "strain" patterns in the presence of a The site of narrowing was in the ascending pulmonary dilated high-pressure coronary circulation. Findings at venous trunk before it joined the left innominate in right heart catheterization showed that two children 7 patients, descending venous trunk entering the portal had pulmonary stenosis, one at valve level and the system in 7 patients, and at other sites in 4. The age of other peripherally. the patients ranged from 11 days to 5 months with equal The methods of assessment of the left heart and aorta, numbers of males and females. 50 per cent had which differed in each case, are outlined, illustrated, and symptoms in the first month of life. They pre- contrasted. sented a recognizable clinical syndrome with laboured Our first case was diagnosed at thoracotomy following respiration, small hearts, signs of pulmonary hyper- percutaneous left ventricular and brachial artery punc- tension, and intense pulmonary cedema. Seven tures only. patients had continuous murmurs, but in the majority Our second child had percutaneous pressure measure- murmurs were unimpressive, so that the underlying ments and right ventricular angiography, which provided heart disease was frequently unrecognized. The dia- an adequate outline of the left heart. gnostic features on the chest radiographs and angio- Our third child had transseptal left heart catheter cardiograms are discussed in detail. studies and angiography from the left atrium. Our fourth patient had retrograde arterial catheteriza- tion following arteriotomy and angiography from the DIFFERENTIAL HYPERCAPNIA IN THE EISENMENGER supravalvar chamber. DUCTUS IN RELATION TO THE DYSPN(EA OF Finally, important negative points in this series are CYANOTIC CONGENITAL HEART DISEASE mentioned-the absence of familial cases, the absence

By Hywel Davies and Nikos Gazetopoulos (introduced) of chromosomal abnormality, and the absence of http://heart.bmj.com/ historical or clinical sequele of hypercalcwmia. Wood pointed out in 1958 that patients with an Eisenmenger ductus were significantly less disabled than those with pulmonary-systemic communications at other levels. This we consider to be due not so much A NEW PLATELET DEFECT IN PATIENTS to the presence of differential cyanosis but rather to WITH ISCHAEMIC HEART DISEASE differential hypercapnia, the blood to the vital centres of the head and neck being not only relatively rich in By Colin Bray (introduced) and Lawson McDonald oxygen but low in carbon dioxide content. The results of exercise studies which demonstrate In a study of platelet aggregation in patients with on September 24, 2021 by guest. Protected copyright. this are presented, and their significance is discussed isch.Tmic heart disease, using Born's technique, some in the context of the determinants of disability in patients patients showed a qualitative difference in the pattern with cyanotic congenital heart disease. of response to diphosphate and adenosine triphosphate. Normal initial aggregation and dis- aggregation of the platelets occurred, but these were SUPRAvALVAR AORTIC STENOSIS followed by a totally abnormal secondary aggregation of the platelets, within two minutes of the initial response, By G. F. Gearty (introduced by R. E. Steen) which progressed to a massive degree. In vivo such mas- Obstruction to left ventricular outflow may occur at sive aggregation could be the starting point of thrombus subvalvar, valvar, or supravalvar levels. Thus aortic formation. On repeated examination of the same stenosis, though usually valvar, is not always so, and patients this secondary aggregation was a constant pressure gradients alone may afford inadequate pre- feature. It never occurred in healthy subjects. The operative assessment. patients who showed this phenomenon were compara- What features then suggest the possibility of obstruc- tively young, had low levels of plasma cholesterol, tion other than at valvar level? How are such cases normal levels of plasma uric acid, and were not deficient best investigated, particularly in children ? in lipoprotein lipase. This previously undescribed One aspect of this problem is illustrated by the recog- defect of the platelets in patients with ischemic heart nition, in recent years, of the syndrome of peculiar disease will be related to a possible metabolic abnormality facies, mental retardation, and supravalvar aortic and to thrombus formation. Br Heart J: first published as 10.1136/hrt.28.3.426 on 1 May 1966. Downloaded from

430 Proceedings of The British Cardiac Society IN ACUTE PROPHYLACTIC VALUE OF PROPRANOLOL By D. C. Fluck, E. Olsen (both introduced), and (INDERAL) IN PECTORIS J. P. D. Mounsey By R. Rabkin, D. Stables, N. W. Levin (all introduced), Bradycardia due either to sudden marked sinus brady- and M. M. Suzman cardia or complete heart block has been observed in 14 In a double-blind trial, 20 patients were given 50 mg. out of 36 consecutive patients admitted to the Intensive of propranolol 4 times daily and placebo, each for 2 Coronary Care Unit at the Hammersmith Hospital. All periods of 2 weeks, according to one of 4 randomized had an acute myocardial infarction and all had con- sequences (ABBA, BABA, ABAB, BAAB). Of these tinuous electrocardiographic monitoring. 20 patients, 4 were withdrawn from the trial (2 defected, The supraventricular bradycardia group consisted of 1 kept inaccurate records, 1 died of myocardial infarc- 7 patients, who had episodes during the first 48 hours of tion). Of the remaining 16 patients, 6 showed no sig- marked sinus bradycardia with a ventricular rate between nificant preference, 10 had considerably fewer attacks on 35 and 55 a minute and an accompanying fall in blood propranolol and of these 2 were totally relieved. The pressure and signs of a vasovagal attack. These attacks average reduction in the number of attacks on propra- were successfully treated by immediately raising the nolol was 44 per cent. The Wilcoxon test for symmetry legs and giving atropine intravenously. Patients prone showed a value of t = + 130 (p =0-001) in favour of the to these attacks formed a clinically recognizable group drug. A carry-over effect was not demonstrated. on admission, all having posterior infarction, a tendency A separate group of 20 patients was treated on a single- to sinus bradycardia (50-60/min.), and severe cardiac blind basis, varying the dosage and the duration of drug pain requiring repeated analgesics. and placebo medication according to the response in The ventricular bradycardia group consisted of 7 each individual patient: this group was observed for patients with complete heart block, 6 of whom came to periods up to 18 months. In 15 there was unequivocal necropsy. In 3, this was a short pre-terminal rhythm in improvement in the frequency and severity of the anginal a dying heart, whereas in the other 4 the heart block was attacks, whereas 5 derived no significant benefit. On more prolonged and associated with Stokes-Adams propranolol therapy, 2 patients died suddenly (one attacks. All 7 patients died. Immediate internal in immediately after mild exercise), cardiac pacing at the onset of heart block temporarily 2 developed acute myocardial infarction, and one had restored sinus rhythm in one patient with clinical left ventricular failure. improvement. The indications for cardiac pacing in Serial laboratory investigations in both trials revealed heart block developing during acute myocardial infarc- no deleterious effects on the hepatic, renal, and hamo- tion are discussed. poietic systems, and untoward side-effects were minimal.

METABOLIC PROBLEMS OF CARDIAC RESUSCITATION CARDIAC IMPULSE IN VENTRICULAR ANEURYSM http://heart.bmj.com/ By K. P. Ball By A. Mourdjinis, E. Olsen, J. Taubman (all introduced), In 21 patients with due to acute myo- and J. P. D. Mounsey cardial infarction arterial blood gas analysis was carried The "paradoxical impulse" of ventricular aneurysm out. The patients were part of a series of 49 patients was studied in 7 patients with proven ventricular aneur- with myocardial infarction in whom resuscitation was ysm following cardiac infarction, using the technique of attempted. Oxygen saturation, carbon dioxide tension, impulse cardiography. In addition, the detailed move- and pH were measured; from these measurements, ments of the underlying aneurysmal wall were examined plasma bicarbonate and oxygen tension were derived. in the cineradiograph and angiocardiogram. Three on September 24, 2021 by guest. Protected copyright. Arterial oxygenation was fairly good in these patients, patients were investigated before and after surgical but they were being ventilated with pure oxygen, and the removal of the aneurysm. Necropsies were performed alveolar arterial oxygen tension gradient was high, in 2 patients and operation specimens examined in 4. indicating severe abnormality of pulmonary function. The aneurysmal wall is composed of collagen and fails As arterial oxygenation was reasonably good, the meta- to take part in concentric contraction of the left ven- bolic acidosis from anarobic metabolism must be due to tricular myocardium during ventricular systole. This poor tissue perfusion. Large arterio-venous differences failure of retraction of the aneurysmal wall was seen in were found in those patients in whom these were the cineradiograph and angiocardiogram. It was also measured. reflected in the impulse cardiogram, in the area over- Acidosis was present in 18 of the patients; in 8 it was lying the aneurysm, where a large sustained outward "respiratory," in 5 "metabolic", and in 5 "mixed movement was prolonged throughout ventricular systole, respiratory and metabolic". Serum lactic levels were replacing the normal inward movement in the latter half raised in all patients in whom it was measured. of systole. After successful surgical removal of the Respiratory acidosis due to underventilation was aneurysm, the cardiac impulse reverted to a more normal surprisingly frequent and severe. Correction of pattem. metabolic acidosis by sodium bicarbonate will only be The sustained impulse ofventricular aneurysmmust be achieved when hyperventilation is produced. Our distinguished clinicallyfrom thatduetoventricular hyper- results suggest that even when this is appreciated ventila- trophy associated with ischmmic heart disease, and the di- tion will not be adequate unless great care is taken to agnostic value of this sign in conjunction with clinical, ensure it. electrocardiographic, and radiological data is discussed.