P970DK-crush is the best treatment strategy to reduce stent oriented clinical outcome, results from a network meta-analysis of twenty-six randomized clinical trials comparing different stent techniques

Background

Coronary bifurcation disease (CBD) accounts for approximately 20% of all and is associated with worse short- and long- term clinical outcomes. Provisional stenting (PS) is the preferred choice, however, this approach may not be suitable in all CBD anatomies, therefore several elective two-stents techniques have been described, however there is lack of randomized evidence to guide interventionalist across different stent techniques. Objectives. To identify the best percutaneous coronary interventions (PCI) technique for CBD.

Methods

We systematically review randomized clinical (RCTs) of patients receiving CBD PCI with either PS or six type of elective two-stent techniques (DK-crush, TAP, culotte, dedicated bifurcation stents, crushing, T-stenting) and compare device oriented clinical events (DOCE) in a network meta-analysis. DOCE was defined as composite of cardiac death, target-vessel myocardial infarction, stent thrombosis, target lesion revascularization OR target vessel revascularisation.

Results

We included 26 RCTs leading to a pooled population of 10339 patients-years with 1229 DOCE. Compared to PS, the DK-crush technique had a lower DOCE with RR=0.62, [0.42–0.92]. Figure. DK-crush had the highest likelihood (model likelihood=90.2%, SUCRA=98.0%) of being the best treatment to reduce DOCE.

Figure 1

Conclusions

In the management CBD, when a two-stent technique is required as upfront strategy, the DK- Crush technique should be privileged as it showed to reduce stent-related clinical outcomes (DOCE) when compared to other bifurcation techniques.

[The viable myocardium: metabolic, diagnostic and therapeutic aspects]

The term stunned myocardium is used to indicate a reversible post-ischemic dysfunction of the ventricular mechanism which may persist for hours, days or weeks after the restoration of coronary flow following spontaneous or pharmacological thrombolysis, transluminal coronary angioplasty, aorto-coronary bypass and ischemic attacks. Hibernating myocardium is used to describe a depression of ventricular contractility in the presence of chronic hypoperfusion which may be reversed following revascularization as a result of aorto-coronary by-pass surgery. Three biochemical and physiopathological hypotheses are currently acknowledged to explain the phenomenon of stunning: the hypothesis of free oxygen radicals, the hypothesis related to an energy deficit and that involving a calcium overload. It is possible that oxydizing stress induced by free radicals may modify the activity of one or more sarcolemmic proteins which regulate the flow of calcium or other ions. Alterations in the transport and accumulation of calcium ions due to a Na+/Ca++ pump deficit and calcium-ATPase of the sarcoplasmatic reticle appear to be responsible for contractile dysfunction. The hypothesis concerning an energy deficit appears to be least probable since even if ATP levels are low the intracellular energy status does not appear to be a factor which limits mechanical function which may be stimulated in the absence of further variations in the content of highly energetic phosphates. There is also reduced myofibrillar creatinkinase activity. In hibernating myocardium the mechanical dysfunction is due to a metabolic and therefore contractile "down-regulation' with low myocardial energy and oxygen consumption to ensure the survival of chronically hypoperfused areas.(ABSTRACT TRUNCATED AT 250 WORDS)

[A critical review of the stable changes in ventricular repolarization in ischemic cardiopathy. A correlation with the angiographic findings]

Unknown is the significance of the abnormalities of repolarization observed at rest in patients with coronary artery disease (CAD) demonstrated by coronary angiography, except for ischemic episodes, myocardial infarction, left ventricular hypertrophy, electrolyte changes or pharmacological interactions. The chronic T wave inversion and ST segment depression are usually considered as an alteration due to ischemia ("chronic myocardial ischemia"); this definition is, in our opinion, erroneous, because myocardial ischemia is an acute episode caused by a sudden lack of balance between demand and availability of myocardial oxygen, corresponding to transient electrocardiographic alterations. Thus, the definition of "chronic myocardial ischemia" referred to stable abnormalities of repolarization is incorrect, because a "chronic" lack of balance between MVO2 and O2 availability would produce necessarily irreversible myocardial damage (necrosis). To contribute to the comprehension of the stable ECG changes at rest, we have selected a group of patients with CAD demonstrated by coronary angiography, presenting stable T wave alterations and ST depression at rest. We have studied the main and regional left ventricular function through radionuclide angiocardiography (ACS). Comparing the abnormalities of repolarization (ECG) on the one hand with angio, EFR and VER on the other, we have obtained different positive correlations, according to the functional parameters considered (EFR and VER). In our study, the lowest positive correlation has been noticed comparing ECG versus angio, VER and EFR (37.5%), while the highest correlation was obtained when ECG was considered versus angio and VER (56.25%). Evaluating ECG versus angio and EFR we have obtained a positive correlation equal to 43.75%. So we have deduced that VER is the functional parameter that better relates to angio and ECG.(ABSTRACT TRUNCATED AT 250 WORDS)

Ergometric evaluation of the effects of enalapril maleate in normotensive patients with stable angina

The anti-ischemic effect of a single oral dose of 10 mg of enalapril maleate (E) was investigated in 14 normotensive patients with coronary artery disease (CAD) and stable effort-induced angina pectoris. An exercise stress test was performed three times in each patient at the same clock hour on three successive days: with no treatment (baseline), 6 h after administration of placebo (P), and 6 h after oral administration of a single 10 mg dose of E. The multistage nonstop effort tests were performed in the sitting position. Workload started at 25 W and was increased by 25 W every 2 min until an ischemic ST depression of more than 1.5 mm was observed. The following parameters were measured: heart rate (HR), systolic blood pressure (BP), rate-pressure product (RPP), workload sustained (WS), elapsed time of effort (ET), and millimeters of ischemic ST depression. The values of the parameters observed with baseline, P, and E were compared at the moment of appearance of chest pain or ischemic ST depression, at the moment of maximal effort, maximal common WS (MCWS), and maximal common RPP (MCRPP). Enalapril delayed the appearance of the ischemic ST depression. At the MCWS, the RPP was significantly lower under E and the ST depression was less marked; this effect was the result of a lower BP level, in the absence of any significant change in HR response. The acute effects of E observed in normotensive patients with effort-induced angina pectoris seems to be related to the inhibition of angiotensin at the coronary level and to its antiadrenergic action.

Does placebo lower blood pressure in hypertensive patients? A noninvasive chronobiological study

Placebo controlled trials have generally been used in order to evaluate the antihypertensive efficacy of drugs. There is some evidence, though, that blood pressure might not be influenced by placebo. Non-invasive devices for automatic blood pressure monitoring are likely to provide a better assessment of blood pressure response to drugs, as well as to different physiologic and pathologic conditions, than the traditional sphygmomanometric devices. The aim of this study was to investigate the effect of placebo on blood pressure recorded automatically and non-invasively. For this purpose, a chronobiologic approach to the collection, evaluation and interpretation of data seemed most appropriate. A group of 12 patients with a clinical diagnosis of essential hypertension underwent automatic blood pressure monitoring in hospital for 4 days. Measurements were taken every 15 min by an oscillometric instrument with an automatically inflated cuff. After a washout period during which the patients received no treatment, pressure recording was undertaken under basal conditions for 2 days. On the third and fourth days of study, the patients received 2 tablets of placebo, one at 10 a.m. and one at 10 p.m. In each patient a highly significant circadian rhythm was documented for systolic and diastolic pressure, both under basal conditions and during placebo administration. Blood pressure mesors were higher than reference standards and were not significantly affected by placebo. The circadian amplitudes and acrophases did not differ significantly before and during placebo. Our data indicate that automatically recorded blood pressure is not influenced by placebo.

Magnesium depletion in patients on long-term chlorthalidone therapy for essential hypertension

Sixty patients were treated for 1 year for essential uncomplicated hypertension, 30 with beta-blockers alone (BB) and 30 with BB and chlorthalidone (CTD). BB did not affect serum K+ or Mg++. In the BB-group there was a statistically significant trend towards retention of Mg++ in a loading test, but the effect was clinically marginal. BB + CTD reduced serum K+ and Mg++ and caused significant Mg++ depletion, as shown by the Mg++ loading test. All the effects were highly significant and were clinically important. The metabolic perturbations due to CTD are potentially dangerous and make this drug unattractive as 'first choice' treatment for hypertension.

Effects of captopril on the physical work capacity of normotensive patients with stable-effort angina pectoris

Twelve normotensive patients with coronary artery disease and stable effort-induced angina pectoris were selected: the antiischemic effect of captopril was studied. A maximal cycloergometer effort test was obtained before (base) and after administration of placebo or captopril (50 mg p.o.). The following parameters were measured: heart rate (HR), blood pressure (BP), maximal rate/pressure product (MRPP), maximal workload sustained, (MWS), maximal working time (MWT), and S-T depression at MRPP. The base and placebo were similar. Compared to them captopril augmented the MWT, increased the MWS, reduced S-T depression at MRPP, and decreased the number of patients with effort-induced angina pectoris. The antiischemic effect of captopril seems related both to its effect on HR and BP, and to a local enhancement of coronary blood flow.

Ergometric evaluation of the effects of captopril in hypertensive patients with stable angina

The antihypertensive and anti-ischaemic effects of methyldopa and captopril were compared in 12 hypertensive patients with coronary artery disease. The antihypertensive effect of alpha-methyldopa (A) and captopril (C) were significant and similar. On the other hand, while methyldopa did not increase the product of systolic pressure and heart rate and did decrease the effort-induced S-T segment depression, C increased the double product (DP) and decreased the ischaemic S-T changes. Captopril might be useful in the treatment of hypertensive patients with coronary artery disease.

Incidence of complex ventricular arrhythmias in asymptomatic patients with recent myocardial infarction

The incidence of ventricular extrasystoles (VES) was documented in 50 patients with recent uncomplicated myocardial infarction, with a 72-h two-channel ambulatory electrocardiogram. All patients were free of symptoms of arrhythmias; unstable angina pectoris and heart failure were absent. A total of 82% of the patients had VES: 23/50 patients had multiform or complex VES, 8/50 patients had ventricular tachycardia. VES were independent of heart rate and stable angina pectoris. Thus, frequent and complex VES are common in asymptomatic patients with uncomplicated recent myocardial infarction. Even in the absence of symptoms, ambulatory electrocardiography is useful. The prognostic significance of asymptomatic complex VES in these patients remains unsettled.

Noninvasive index of cardiac contractility during stress testing: a collaborative study

The present study was conducted in parallel in three different institutions with a similar purpose but using different technical setups. Based on the experimental demonstration that the external phonocardiogram is similar to the rate of acceleration (d3P/d3t) of the left ventricular pressure, and that catecholamines in a similar way increase the early positive wave of the left ventricular pressure and the first heart sound (S1) of the external phonocardiogram; knowing that exercise causes secretion of catecholamines and sympathetic reflexes, we have studied the S1 changes as a result of exertion in 34 normal young subjects. Blood pressure, heart rate, electrocardiograph, and phonocardiograph recordings of each subject were taken. In 10 subjects, cardiac output was also recorded by impedance cardiography. The result of the study was that the first heart sound increased routinely 4-5 times the normal amplitude; in a few subjects the increase was up to 15 times greater. While the extent of increase of S1 was proportional to the severity and duration of the effort and was usually proportional to the increase of other parameters, exceptions were noted as having marked increase of S1 with moderate increase of either blood pressure or heart rate. This was explained by the different receptors activated by the catecholamines and by the complexity of hormonal and neural influences acting on various organs in a stress test. The amplitude of S1 was found to be a reasonably reliable index for following changes of cardiac contractility during exercise, and the suggestion was made that this parameter should be studied in parallel with the others in routine stress tests.

Antiarrhythmic use of cibenzoline, a new class 1 antiarrhythmic agent with class 3 and 4 properties, in patients with recurrent ventricular tachycardia

Cibenzoline is a new antiarrhythmic agent with class 1 properties, and additional class 3 and 4 effects. We treated 28 patients with drug-refractory and recurrent ventricular tachycardia with up to 700 mg/day cibenzoline for periods up to 5.5 months. Cibenzoline prevented the recurrence of ventricular tachycardia in five patients (18%). In three patients (11%) the arrhythmia may have been worsened, in 23 patients (82%) cibenzoline was ineffective. Cibenzoline increased the PR interval by 18% and the QRS duration by 33%; the effect on the QT was variable and the corrected QT interval did not change significantly. Side-effects were observed in 21% of patients. We conclude that cibenzoline does not appear to be superior to conventional class 1 antiarrhythmic agents and that it cannot be recommended for general use in patients with ventricular tachycardia. Additional pharmacokinetic and electrophysiologic studies are required before cibenzoline is used in outpatients with severe ventricular arrhythmias.

Vasodilator treatment for mild to moderate heart failure. Effect of Ro 12-4713, a minoxidil analogue

18 patients (14 men, 4 women) with a mean age of 64.3 years (range 41-75) and with chronic cardiac failure, NYHA functional class 1-2 (12 cases) or 2-3 (6 cases), insufficiently responsive to digitalis and diuretics, were treated for 4 weeks with Ro 12-4713, a minoxidil-like drug. The effects were assessed at rest and during maximal exercise, each patient was his own control. All patients completed the study. The treatment did not affect the body weight, the heart rate or the blood pressure, but it should be stressed that all patients were normotensive. The ejection fraction (by 99mTc pertechnetate scintigraphy) increased from 42.0 +/- 10.0 (resting means +/- SD) to 48.9 +/- 8.7%, and from 44.7 +/- 10.1 to 57.9 +/- 8.7% (end-exercise values), both changes being significant (p less than 0.0001). The ejection rate increased in a similar manner. The resting stroke volume increase from 53.5 +/- 13.6 to 60.2 +/- 16.5 ml (p less than 0.005), but the exercise stroke volume did not increase significantly. The cardiac output increased both at rest and during exercise, but the changes did not reach statistical significance. The end-diastolic volume decreased from 132.6 +/- 126.9 +/- 47.0 to 126.9 +/- 42.3 ml (resting values), and from 151.5 +/- 44.4 to 120.6 +/- 36.6 ml (exercise), the changes being significant (p less than 0.005). The physical work capacity increased, i.e. the duration of exercise increased from 7.8 +/- 3.2 to 9.9 +/- 1.9 min (p less than 0.05) and the 'quality of life' (symptoms related to heart failure) improved (fewer symptoms) in 14/18 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Some biochemical platelet patterns in stable coronary patients

Patients affected by stable angina pectoris whose platelets were characterized by ultrastructural alterations, were investigated in some biochemical changes of their platelets. A decrease of P.A.R. (platelet aggregate ratio), an increase of MDA production in particular conditions, nevertheless a stability of cAMP content in platelets, even after thrombin stimulation, were found.

Tiapamil in the management of supraventricular arrhythmias occurring after acute myocardial infarction

18 patients with acute myocardial infarction and sustained supraventricular arrhythmias were treated with tiapamil, in a dose of 1 mg/kg i.v. The drug was effective, i.e., the heart rate was reduced to less than 90 beats/min in 9 of 10 patients with atrial fibrillation, in 3 of 4 patients with atrial flutter, and in 3 of 4 patients with atrial tachycardia. The peak effect was observed within 2-5 min. In cases with recurring tachyarrhythmias, tiapamil was also effective during successive administrations, the systolic blood pressure was reduced by 10-15%, but severe hypotension was not observed. In these patients, no major changes in atrioventricular or intraventricular conduction were observed. In the dose used, tiapamil was effective and well tolerated.

Antihypertensive effects of a novel peripheral vasodilator, Ro 12-4713

The effects of Ro 12-4713, a vasodilator, on blood pressure and heart rate, were tested in 13 ambulant patients with mild to severe hypertension. The patients received Ro 12-4713 in total oral doses ranging from 1.5 to 4 mg/kg over a 3-5 day period. Standard laboratory tests were done 24 h before and after the study. Standing and supine blood pressure and heart rate were determined before, and every hour for 6-8 h after drug administration. ECGs were recorded before, during and at the end of each study day. Ro 12-4713 reduced the pretreatment standing and supine-blood pressure from 213 +/- 34/126 +/- 21 mmHg and 218 +/- 31/130 +/- 20 mmHg to 156 +/- 33/85 +/- 9 mmHg and 158 +/- 25/88 +/- 11 mmHg at the end of Day 5. Heart rate was only transiently increased in patients with pretreatment values of less than 90 beats/min. Although abnormal ECGs tended towards normalization, there were 2 cases of T-wave inversion (the patients remained asymptomatic). Raised BUN levels tended to decrease towards normal. Side effects reported spontaneously by patients (headaches, palpitations, dizziness, nausea and one case of water retention) appeared to be transient in nature. Ro 12-4713 appeared to be a very potent and long lasting antihypertensive agent, whose inherent side effects were only transient in nature.

[Evaluation of coronary heart disease by kinetocardiography and electrocardiography before and after injection of dopamine and isoproterenol]

Eighty patients with coronary insufficiency, with or without infarction, were studied by kinetocardiography and electrocardiography before and after the infusion of dopamine (40 patients) or isoproterenol (40 patients). Twenty healthy subjects for dopamine and 20 for isoproterenol served as controls. The basal ECG has a moderate (52.5%) sensitivity and a high (92.5%) specificity. KCG-25 has a poor (19,7%) sensitivity and a high (95%) specificity. KCG-45 has a high (76.2%) sensitivity and a moderate (50%) specificity, 25/40 healthy subjects had at least one pathological finding: either the ECG or the KCG-25 or the KCG-45. The mechanisms and the relevance of the false positives of the KCG are reviewed. In spite of different pharmacological properties, there is no statistical difference in the effect of dopamine and isoproterenol on the ECG and KCG. The KCG may be considered equivalent to the ECG, taking into account that it brings different information. The infusion of dopamine or isoproterenol induces dyskinesia in some patients with coronary insufficiency. Only two statistically significant changes were observed: dopamine increases the sensitivity of KCG-25 (up to 44.4%) and the specificity of KCG-45 (up to 95%). In selected cases the infusion of dopamine may be a useful test.

Torsades de pointes as a manifestation of mexiletine toxicity

An episode of torsades de pointes, an unusual ventricular tachyarrhythmia, developed in a 59-year-old coronary patient who was treated with 100 mg. four times a day mexiletine orally. The PR, QRS, and QT intervals were normal. The ventricular arrhythmias resembled in part, the patient's previous ventricular premature complexes, but there were some relevant morphological differences. The plasma electrolytes were within normal limits. Mexiletine, which is chemically and electrophysiologically similar to lidocaine, probably caused this arrhythmia. Although mexiletine is a useful antiarrhythmic drug, it should be added to the list of drugs associated with atypical ventricular tachycardia.

Influence of propranolol and pindolol on the haemodynamic effects of papaverine, isoprenaline and noradrenaline in hypertensive patients

The influence of two beta-adrenoceptor antagonists, propranolol and pindolol, on the haemodynamic effects of papaverine, isoprenaline and noradrenaline was investigated in 9 male patients with first degree essential hypertension. Propranolol and pindolol were given according to a doubleblind, crossover scheme. Heart rate and blood pressure were measured before and after each treatment. Propranolol 670 microgram/kg i.v. reduced the supine and standing systolic blood pressures by 2.3% and 1.6%, respectively. Similarly, the intravenous administration of pindolol 35 microgram/kg reduced supine and standing systolic blood pressure by 5.5% and 8.3% respectively (clinically insignificant). Neither drug affected diastolic blood pressure. Following propranolol, there were moderate reduction in supine and standing heart rates, respectively by 24% and 20% (p < 0.001). Similarly, but to a lesser extent, pindolol reduced supine and standing heart rate by 12% and 17% (p < 0.001). The effects of papaverine, which, at 1.5 mg/kg i.v. reduced systolic blood pressure by 5-10% and increased heart rate by 8-15%, were not significantly influenced by the beta-blockers. The blood pressure and heart rate responses to isoprenaline, on the other hand, were attenuated or inhibited by both beta-blockers. While the beta-blockers inhibited the beta-adrenoceptor component of noradrenaline, the pressor component of noradrenaline, which is mediated through the alpha-adrenoceptors, was not influenced by propranolol, but was inhibited after pindolol. It is concluded that pindolol differs qualitatively from propranolol in that it inhibited both the alpha and beta-adrenoceptor effects of noradrenaline.

The therapeutic value of clonidine in patients with coronary heart disease

11 coronary patients, 8 with mild hypertension, were treated with clonidine, at a dose of 75 micrograms b.i.d. per os for a week. The effect of the drug on coronary heart disease was assessed by means of a symptom-limited multistage exercise test on the cycloergometer. Clonidine was effective in reducing the exercise-induced increases in blood pressure (by 15.5 +/- 6.1%), the double product (by 34.8 +/- 20.8%) and the electrocardiographic ischemic changes. In 2/4 patients, effort related ventricular extrasystoles were reduced by greater than 50% after clonidine. The drug worsened the anginal pain in 3 and relieved the pain in 3 patients. However, it reduced the exercise-induced ST-T segment downsloping in 7 patients. The tolerance was good, since only 3/11 patients reported slight dry mouth, sedation and pyrosis. In view of the electrocardiographic effect, further studies with clonidine on myocardial ischemia should be performed.

Therapeutic effects of pindolol and nifedipine in patients with stable angina pectoris and asymptomatic resting ischemia

A single blind randomized parallel study designed to assess the anti-anginal efficacy of pindolol and nifedipine was carried out in 42 ambulatory coronary patients with stable angina pectoris. Drug efficacy was assessed in terms of (a) pain, (b) frequency of anginal episodes, (c) nitroglycerin consumption, (d) exercise tolerance and (e) ST-segment changes. The effect of these drugs on asymptomatic resting myocardial ischemia was also assessed by means of 24-h dynamic electrocardiography (DCG). All patients were checked at weekly intervals. At the end of a 4-wk placebo period, the patients were randomly assigned either to the pindolol or nifedipine group. The treatment lasted for 45 days. During the placebo period, ischemic ECG changes and symptoms of coronary insufficiency were detected in all patients. Furthermore, 12 out of 42 patients had asymptomatic myocardial ischemia at rest. One patient from each group was dropped because of tolerance. At the end of the 45-day study, pindolol and nifedipine were equi-effective on spontaneous and effort-related angina. There were, however, some differences: increased tolerance to exercise appeared earlier with pindolol: the pindolol group showed a slightly reduced while the nifedipine group showed a slightly increased heart rate. Furthermore, nifedipine reduced or eliminated asymptomatic myocardial ischemia in 6 out of 7 patients while only 1 out of 5 improved in the pindolol group.

Human electropharmacology of the calcium antagonist dimeditiapramine (Ro 11-1781) in coronary patients

The electrophysiological effect of dimeditiapramine (Ro 11-1781), a Ca2+ antagonist, was evaluated in 20 patients with coronary heart disease. Electrophysiological measurements, including sinus cycle length, sinoatrial conduction time, intra-atrial conduction time, atrial, atrioventricular, nodal and ventricular refractory periods and intraventricular conduction time were recorded before and after the intravenous administration of Ro 11-1781. At a dose which is effective against cardiac arrhythmias, Ro 11-1781 produced no statistical significant changes in the sinoatrial and intraventricular conduction time. Similarly, neither the sinoatrial nor the ventricular refractory period was affected. Ro 11-1781, however, increased the atrioventricular conduction time and decreased the systolic blood pressure to a statistically significant extent. The tolerance was very good.

Dimeditiapramine (Ro 11-1781), a new calcium antagonist, in the management of supraventricular tachyarrhythmias in patients with acute myocardial infarction

18 patients with acute myocardial infarction and sustained arrhythmias were treated with a new Ca2+ antagonist, Ro 11-1781, at the dose of 1.0 mg/kg i.v. The drug was effective in reducing heart rate to less than 90 beats/min in 9/10 patients with atrial fibrillation, in 3/4 patients with atrial flutter and in 3/4 patients with supraventricular tachycardia. The peak effect was observed within 2--5 min after the intravenous administration of Ro 11-1781. In cases with recurring tachyarrhythmias, the drug was also effective in repetitive administration. Systolic blood pressure was reduced, but severe hypotension (less than 90 mm Hg) was not observed. The atrioventricular conduction in these patients remained unimpaired and asystole did not occur. The drug appears to be an effective and a well tolerated antiarrhythmic agent.

Disorders in peripheral arterial system in asymptomatic elderly: plethysmographic semiology at rest, during postural, effort and pharmacological tests

The vascular system of 30 old asymptomatic patients (average age 62.5 years) was studied by reflection plethysmography. The plethysmogram (PTG) was recorded from the forefinger of the left hand at rest, during two postural tests (+45 degrees arm-up and -45 degrees arm-down), after physical work, and during the infusion of nitroglycerin and the beta-agonist metaproterenol. 50% of the subjects presented a normal PTG under basal conditions. However, pathological PTGs were recorded after the various tests: 23.3% with the arm-up test, 6.6% with the arm-down test, 52% with the effort test, 31% with the nitroglycerin test and 73.9% with the metaproterenol test. Clearly, the effort and metaproterenol tests are pathological in the majority of cases, both tests inducing physiologically vasodilation and increase in the peripheral pulse. The arm-down test, which usually induces vasoconstriction, is almost always normal. Since the percentage of pathological responses to the nitroglycerin test is significantly smaller than that to the effort and metaproterenol tests, it is concluded that the vascular changes induced by aging are primarily functional, at least in asymptomatic subjects. Aging more negatively influences the vasodilating than the vasoconstricting ability.

Initial clinical experience of lorcainide (Ro 13-1042), a new antiarrhythmic agent

Lorcainide is a promising antiarrhythmic agent that belongs to the class of local anesthetics. It was tested in 7 patients with malignant ventricular arrhythmias that were resistant to other antiarrhythmic agents. Lorcainide was effective in all cases (complete disappearance of arrhythmias in 6 cases and more than 50% disappearance in the 7th case), and the tolerance was within acceptable limits. The drug was effective at rest, as assessed by 24-h dynamic electrocardiographic monitoring, and during physical exercise. Longer studies with more patients are warranted, since the drug appears to be a promising antiarrhythmic agent.

[Hemodynamic and electrocardiographic effects caused by intravenous infusion of a tricyclic antidepressive agent dibenzepin]

The cardiovascular (blood pressure, heart rate, central venous pressure) and ECG changes caused by dibenzepine-infusion (720 mg/day for 48 hours) have been assessed. Mean blood pressure and heart rate did not show significant changes. In some patients, however, distinct changes in both variables were observed. Central venous pressure was not affected. The infusion elicited changes in the repolarisation phase of the ECG: it did not, however, alter either the automaticity or the conductivity of the heart. These results were obtained in 40 depressive patients, whose general conditions and cardiovascular state were excellent and must not be extrapolated for cardiopathic patients. The risks inherent in this therapeutic approach are discussed.

The kinetocardiogram during the isoproterenol test for the assessment of coronary heart disease

50 patients, 20 without heart disease and 30 with coronary heart disease (CHD), were studied by kinetocardiography (KCG), before and after administration of isoproterenol (initial dose 2 microgram/min, maximum dose 6 microgram/min). In the control subjects the KCG was unaffected by the drug. In contrast, in most of the patients with CHD isoproterenol induced the appearance or the increase of paradoxical systolic bulges, which are regarded as the expression of ventricular dyskinesia resulting from isoproterenol-induced transient regional ischemia. This test is recommended as a valuable noninvasive method for the diagnosis of ischemic ventricular dyskinesia.