Aust. N.Z. J. Med. (1979,. 9, pit. 736-768
The Cardiac Society of Australia and New Zealand Annual Meeting, 1979
The following are abstracts of papers presented at t h e A n n u a l Meeting of T h e Cardiac Society of Australia and New Zealand, held in Adelaide from 2-4 May, 1979.
CIGARETTE SMOKING IN NEW ZEALAND-THE SIGNIFICANCE OF THE 1978 CENSUS RESULTS
REGRESSION OF ATHEROSCLEROSIS? EFFECTS OF A SUBSTANTIAL SERUM CHOLESTEROL DECREMENT
D. R. HAY
L. A. SlMONS. J. J. MORGAK,J. P. ISHISTI~K and J. C . GIRSOX
National Heart Foundation of New Zcaland, 7111.Princes.? Margaret Hospital. Christchurch, NeM Zealand
More than two million men and women over 15 years responded to a question on cigarette smoking in the 1976 population census. Thirty-eight per cent of men and 319; of women were regular cigarette smokers (one or more cigarettes per day), a relatively low figure by international standards. More Maori women (579;) smoked than Maori men (5376) while men from the Pacific Islands smoked more heavily than European. Smoking is more prevalent in younger age groups, particularly in women and in Maoris. Forty-one per cent of all men aged 20- 24 are smokers, 42% of them exceeding 20 cigarettes a day. In the same age group, 38% of women are smokers with a third smoking more than 20 cigarettes a day. Two-thirds of Maori women aged 20 --24 are regular smokers. Smoking is strongly correlated with occupation. income and marital status. About one in four men in the various professions are smokers compared with double this figure for those in unskilled occupations. Those in the highest income groups smoke least while there is a high prevalence in the divorced and legally separated. The prevalence of smoking in New Zealand has fallen and is lowest in those With higher educational attainments. This may indicate a positive response to health education; alternatively, the continued high rate of smoking in young people and in the lower socio-economic groups may imply a failure of present educational methods. Special challenges are posed by the Maoris, whose coronary disease mortality rates are rising at a time when there has been a fall in the nonMaori rates.
Departments of Medicine, Cardiology and Haernatology, St. Vincent’s Iiospital. Sydney, N S W
The reversibility of advanced atheromatous lesions in man seems doubtful. Intervention for hypercholesterolaemka has failed to yield unequivocal evidence of improved coronary heart disease mortality. It is argued that such interventions fail to achieve an effect on mortality because an insufficient decrement in serum cholesterol results. This question has been studied through aggressive cholesterotlowering therapy in three patients with heterozygous familial hypcrcholesterolaemia, who have angiographic evidence of coronary artery disease (CAD). The patients have been treated for over 22 years by a combination of plasma exchange and nicotinic acidclofibrate (Atherosclerosis 31( 1978)195). Prior to or early in the course of therapy, coronary angiography was performed using the Sones technique. This was repeated about 2$ years after commencement of the relevant therapy. The clinical data and biochemical results are summarised in the table.
Initial Final cholesterol cholesterol Age Ser mmol I mmol 1
Initial coronary allglOsrdphy
6.8 7 - 8
CAI). 2 veascls
C A D . 3 vessels
CAI). 2 vessels Abn. left vent.
Despite successful and substantial cholesterol-lowering therapy in all three patients, significant regression of their
D E C L M H ~1979
THE CAKDIAC SOCIETY 0 1 A
CAD W:IS not observed. The angiographic picture in B.I. showed unchanged involvement of the Right and Circumflex Coronary Arteries. M I . showed definite increase in Right Coronary Artery obstruction. while L.C. showed further arterial obstruction and deterioration in left ventricular function. From the clinical viewpoint. all patients were unchanged. It i s concluded that the achievement of substantial scruni cholesterol decrements in three patients with familial hypercholesterolacmia and advanced coronary atherosclerosis was unable to induce any regression in thc lesions. It is uncertain whether the rate of progression was slowed or not.
BETA-BLOCKERS A N D HIGH DENSITY LIPOPROTEIN LEVELS J . D. 1 . ENGIAluD, L. A. and M. CAmrox
J . C. cJ1BsoS
Katoornba Medical Centre; School of Medicine, Universitj of NS W and St. Vincent's Ilospitul. Sydriej Potential metabolic effects of beta-blocking drugs have assumed increasing importance as more young patients commence life-longtherapy for hypertension. With respect to lipids, beta-blockers have been shown to increase triglyceride levels. while they may reduce the level of high density lipoproteins (IIDL). The present study was designed to examine the effects of mctoprolol and atenolol on plasma lipoproteins. Thirty-four patients were studied using a single-blind croamver design, with three months on each drug separated by ten day placebo washout period. Fasting plasma lipids were measured on a single occasion at the end of each treatment period. HDL cholesterol was measured b>- a precipitation method and lipoprotein proteins by immunoassay. Compared with placebo values. neither beta-blocker influenced total plasma cholesterol levels, while total plasma triglycerides increased slightly. Low density lipoprotein level remained unaltered, while H D L cholesterol and protein was significantlyreduced by both beta-blockers. The ratio of total cholesterol to HDI. cholesterol was thus increased by both drugs. _ Cholesterol
H D I . Cholesterol
I i y w x t
*/' < 0 0 3 . +I' < 0 ~ 0 5
In view of the recent evidence linking a reduced H D L level with increased heart disease risk, the present findings suggest that patients taking these beta-blockers (and possibly others) over many years may be exposing themselves to increased vascular risk, despite other anticipated benefits from such therapy.
CORONARY ARTERY GRAFTING IN SOUTH AUSTRALIA 1970-1978
G. R. NU", D. R. CRAI>IKK;K, 1. K . Ross, J. I'YM, J . L. WADDYand L. SWANEY Cardio-thoracic Surgical Cnit , Rqvd Adelaide Ifo.spitul, South Australia
All open heart surgery in South Australia is concentrated in one Unit at the Royal Adelaide Hospital. Coronary artery grafting began there in 1970 and by the end of 1978. 1,611 patiehts had undergone surgery. This figure excludes those patients who underwent coronary artery grafting plus an associated procedure such as aneurysmectomy or valve replacement. The hospital mortality for the entire period was 2.4'9,. The portion of the total opcn heart work load of the State occupied by coronary artery grafting has progressivcly risen from lo,, in 1970 (one case out of 124) to 74"; in 1978 (574 cases out of 776). A similar picture is seen when the combined workload of the four cardiac laboratories of the State is examined, since in 1970 only one per cent of catheter studies were undertaken in order to provide a coronary angiogram but by 1978 this figure had increased to 70:, (1,045 out of 1,494 investigations). Increasing local confidence in the ability of the operation to relieve angina has led to a progressive increase in the number of patients presenting for investigation and surgery with the result that the number of grafting operations performed in 1978 rcpresent a 71",, increase on those for 1977 (574 compared to 336) and equals 46 operations per 100,000 people on a State basis. Although the majority of patients (910 out of 1,611) werc submitted to operation during 1977 and 1978,it was thought worthwhile examining the results of the procedure in an effort to assess whether the encouraging early relief of symptoms has been maintained.
HYPOTHERMIC CARDIOPLEGIA: A N EXPERIMENTAL AND CLINICAL ANALYSIS OF COOLING TECHNIQUES
F. L. ROSENFI!I.DT, G. K.STIRIJNG and G. R. DAWY Baker Medical Research Institute and C. J . Officer Brown Cardiac Surgery Unit, rilfred Hospitul, Melbourne. Victoria The combination of local cardiac hypothermia and chemical ~ cardioplegia during open heart surgery produces excellent operating conditions and ;I high degree of protection of the myocardium against ischxmic damage. Of the two modalities of protection h! pot hermia is the more powerful and the degree of protectioii increases with progressive lowering of myocardial tcmperat tire. The aim of the present study wiis to examine the factors causing rewarming of the myocardium during hypothermic cardioplcgia and to discover ways of improving current techniques of producing local cardiac hypothcrmia. An in vitro model was devised of the thermal conditions of opcn heart surgery. Excised animal hearts were cooled under controlled conditions in the model and the cooling patterns recorded using myocardial thermocouples. The validity of the model was established by comparing cooling curves of five dogs' hearts recorded in the animal on bypass and then in the model. Heat sources and cooling methods were then studied in 16 excised pig hearts using the model and also in 12 dogs on bypass.
ARS 1R A (
Marked interference with cardiac cooling was produced by a pulmonary venous return at or above 100 ml.min, ineffective decompression of the right atrium and failure o f cold saline to irrigate the entire cardiac surface. Significant cardiac rewarming occurred when bright theatre lights o r warm room air were combined with a low level ofcold saline in the pericardium. Cardiac coolin!: by external lavage was improved b) irrigating the entire cardiac surface. increasing the f o w of cold saline up to 350 ni1.min and by progressively lowering the temperature of the saline. By placing a plastic mesh pad (spacer) behind thc heart which allowed an unimpeded flow of coolant the temperature of the posterior wall o f the left ventricle was lowered by 10 C. Aortic root perfusion with saline at 4 C lowered septa1 temperature by 10 C in 2j-0.2 mins compared with ? 1 + 1 - Y mins ( P c: 0.01) for Shumway's Technique of cooling by external irrigation. To enable these investigations to be extended to the clinical area miniature temperature probe 4 Mets. S3 includes normal housework, light gardening. golf with cart, while S4 contains heayier gardening. window cleaning. bricklaying etc. In the
L l i i r r r s i r j - (if', Y i r i ? i i i ~ & ~ i ~ m d East Hirrtiirinamic and operative assessment of the magnitude of the shunts and tho si/e of the defect. An additional group of patients with the clinical suspicion of an atrial heptal defect but normal haemodynamics were studied for comparison. A right ventricular internal diastolic diameter of over 35 mm was found at echocardiography in the majority of patients with an atrial septal defect proven haemodynamically and at surgery. I n no patient was the right ventricular diameter less than 30 rnm. Paradoxical septal motion was present in 3 3 of the 36 patients prc-operatively. C'orrelations u w e made b e t w c n the echocardiographic right ventricular diameter. the degree oflelt to right shunting, thc mean pulmonary artery pressure at rest. and the size o f (he defect assessed at surgery. Post operative echocardiograms were performed at varying intervals following surgery to asxss the changea in the right ventricular dimensions Li)llowing closure o f the dcfcct. There was a mean reduction of 15 mm in the right ventricular diameter post-operatively. Septa1 motion returned to normal in the majority of patients. The value of echocardiography as a diagnostic tool to avoid catheterisation was determined.
SE PTAL MOTlO N, VE NTRlCU LAR VOLUME AND FUNCTION BEFORE A N D AFTER ATRIAL SEPTAL DEFECT CLOSURE I N ADULTS
J. €k?K;.D. T, KEI 1.Y. D. K. RK'IIMONI) and R. I... I.JKI:N Ikpcirtiiicwt of Curdiologj, cmd .Vrrc~lrori 2 f e d i c . k Koyul P r i n w Aifi.ed Hospital,
Cuitl/~l~rclou.n, NS M'
The mechanism of abnormal interventricular septal wall (IVS) motion, an important echocardiographic feature of atrial septal defect (ASD), was studied by radionuclide cineveiitriculography. In nine adults with ASD, aged 20--53. the IVS motion was assessed in the left anterior oblique projection before and within two weeks after ASD closure (pre-operatively and post-operatively). Right ventricular (RV) size and left ventricular ejection fraction (LVEF) were also measured before and after ASD closure. In the normal patient in diastole the IVS assumes an anterior curvature and in systole contracts concentrically. The IVS motion was adequately visualiscd in eight out of nine ASD patients preoperatively. and was abnormal. In diastole the IVS was posteriorly displaced into the cavity of the left ventricle and the anterior curvature was flattened. In early
9, NO. 6
systole the IVS returned to its normal anterior curvature, resulting in apparent systolic anterior motion, but the IVS contracted normally. Post-operatively all but one patient showed a return to the normal diastolic IVS curvature. R V size was diminished significantly early after ASD closure (RV to LV volume ratio 3 , 7 2 0 . 4 (SD) preoperatively v. 2 . 0 k 0 . 6 post-operatively. P 1 3 to 1.5 cm), and severe LVH (> 1 5 cm). Results:
- - ... .- ..-. .- - .. ..
.- . . ..
ECG NI LVH (volt) LVH&S* Other
.. - .
- ..- _- -
27 13 6 9
Fxho data .-
Moderate Severe LVH LVH
- .. ......- - .. . -... .-. .- - 10 4
-_ 1 - - -. .__
__ __ 14
2 3 5
- - _- - . - - - . .-.. 55
. ... . ..-.. ._ -
4 -. ...- - -.
*Patients with LVH & S all had severe or long-standing HT
Conclusions: 1. LVH on echo was present in slightly more than half of these HT patients with normal ECGs. 2. LVH (volt) falsely diagnosed LVH in 5/13 patients. 3. Therefore, echo appears essential in the reliable diagnosis of LVH in mild hypertension.
THE CARDIAC SOCIETY OF .4USTRALIA AND NEW ZEALAND
NON-INVASIVE PREDICTION OF MULTIVESSEL.DISEASE AFTER MYOCARDIAL INFARCTION
R. F. WJNN, B. FREIDMAN, 1. K. BAILEY, R. U R E S and D. T. KELLY Hallstrom Institute of Cardiology and Department of Nuclear Medicine, Hoyul Prince Alfred liospitul, Sydney The prognosis of patients after myocardial infarction (MI) is partly determined by the extent of the coronary artery disease. Any non-invasive method which reliably identifies this will help in patient management. Fifty patients with prior single transmural MI (25 anterior, 25 inferior) were studied by exercise electrocardiugraphy (E.ECG) and serial exercise thallium-201 (TI-201) myocardial perfusion scanning (MPS) to see if single or multi vessel disease could be predicted. Coronary arteriography was performed in all patients and significant coronary artery disease was graded as 2 70:0 obstruction in one or more vessels. Eighteen patients had single vessel disease (SVD) and 32 patients had multivessel disease (MVD), (21 with two vessel disease and 11 with three vessel disease). The E.ECG was positive ( > 1 nini ST segment depression or elevation) in 28 of 50 patients; five of 18 (28"/,) with SVD, 23 of 32 (72"/;,)with MVD ( P < 0.005). In the 28 patients with a positive E.ECG 23 (8296) were found to have MVD and in the 22 patients with a negative E.ECG 13 (SY",,,) had SVD and nine (4l"(,) had MVD. A positiveT1-201 MPS (perfusion defect at a site other than the infarct) was present in one of 18 patients with SVD (67") and28 of32patients(887b)withMVD(P. U . HC'N'I l ~ i ~ / ~ ~ l r ~ l ? l of c ~ lC i i' l i r f i ~ ~ tIr' ll f t r r l l l t r c ~ o l o , ~Bj ~7llc,r.crpc,liric~.\ (ill(/ / ) l ~ / J t i ~ f f l f i O ' ffl' ~( ' ( i K d ; O / O ~ j ' .
Tlrc Rojwl . W r l h o r r r ~ ~1if~o s p ; i ~ ~II ic'toricr . A recent survey showed that 40'',, of liospital patients, who were regular users of from fresh tablets ( I > < 0.001) and those tahlcts which were hept in the original hottles had significantly greater amounts of GTN than those tran.;ferreti to other containers o r pill hoses (1' \ 0 . 0 5 and I' < 0 . 0 0 5 . 1-cspectivcl)). 1-here was ii significant dil'fercnce bctbveen tablets l'rom other containers and those a hich l i d been kept in pill hoses (I' c 0.OI ). All o f these changes were alsn time related. The greatest losses occurred in the first \veek and were accelerated hy t1-atisli.r from the original hottle to an! other containcr. As exposure t o air facilitates the loss of GTN froni tablets, the effect of the frequency of opening containers was also studied for one week. Groups ofthree bottles were opened I , 3, 4 or 10 times each day in an air conditioned r o n i i i . Tablet.\ were assayed on Days 0. 3 and 7. Under these conditions the loss of G TN froni 0 t o 3 days \v:is I-elated t o the number of opcnings each day. By 1 h y 7, tilthough total losses W C ~ C greater. the difference hetwcen t i u r iincl ten times per cia) \vas less distinct. From this study i t would a p p i r that significant lo GTN occur niice patients have heen using the tahlcts Ihi- ii week o r inore. The losses arc greatest i f the tahlcts arc traiisferrcd t o pill hoses ;mi o r esposed to the air on m a t i ) occasions. The activity of the tablets is best preserved in the original bottles, but these arc an.kward for everydn! use. I t is 7