Improved outcome of coronary stenting by utilizing a modified treatment protocol

Coronary stents improve patient outcome, are easy to deploy and are now being utilized very frequently after coronary angioplasty. New protocols have been suggested to overcome the main limitations of stenting, namely subacute stent thrombosis, local vascular complications, and the length of hospitalization. In this report we describe our current results with coronary stenting in 100 patients: we modified our standard protocol and used high pressure noncompliant balloons to expand the stent, added ticlopidine to some of the patients to inhibit platelet activity, and used the transradial approach in some patients to reduce the risk of vascular complications. These results were compared to those obtained in our initial group of 50 patients in whom we used a standard implantation protocol. Subacute thrombosis occurred in one patient in the current group of patients compared to five patients in our early experience (P = 0.026). There was no change in local vascular complications. This preliminary report shows that subacute thrombosis can almost be eliminated by the new stent implantation protocols. Less aggressive anticoagulation and radial artery catheterization can decrease vascular complications.

Importance of delaying balloon angioplasty in patients with unstable angina pectoris

Angioplasty in patients with unstable coronary artery disease is associated with higher complication rates compared with patients with stable disease. In this report we describe our results from a group of patients with unstable disease (unstable angina pectoris and postmyocardial infarction) where a strategy of delaying angioplasty for > 5 days after admission was undertaken. Included are 2069 consecutive patients: 1197 treated for stable angina pectoris and 872 treated during admission for unstable angina or myocardial infarction. There was no difference between the two groups in angioplasty success (92.1% stable, 92.3% unstable), failure to dilate without complication (6.4% stable, 6.1% unstable), or in the rate of major complications: death (0.5% stable, 1.1% unstable), Q-wave myocardial infarction (0.9% stable, 1.1% unstable), and emergency coronary artery bypass (0.6% stable, 0.3% unstable). The duration of hospitalization following angioplasty was longer in the unstable group (5.6 +/- 8.1 days vs. 4.2 +/- 4.1 days; p < 0.001) because of longer duration of heparin infusion. There was no difference between groups in minor complications such as groin hematoma and pseudoaneurysm, renal failure, or infections. It was concluded that delaying angioplasty in unstable patients for > 5 days after admission is a safe and effective therapeutic strategy for this group of patients. The need for prolonged heparin infusion after angioplasty is increased in unstable patients and thus the duration of hospitalization after the procedure is longer.

Apparent desensitization of a sigma receptor sub-population in neonatal rat cardiac myocytes by pre-treatment with sigma receptor ligands

sigma Receptor ligands induce marked effects on contractility in cardiac myocytes from neonatal and adult rats (Ela et al., 1994, J. Pharmacol. Exp. Ther. 269, 1300-1309; Novakova et al., 1995, Eur. J. Pharmacol. 286, 19-30). Augmentation or attenuation of the contractile amplitude was observed under different experimental conditions. Preincubation of neonatal cardiomyocytes with a sigma receptor ligand ((+)-(3-hydroxyphenyl)-N-(1-propyl)-piperidine ((+)-3PPP), (+)-pentazocine, or haloperidol) changed the response to re-application of the ligand after cell wash. The inhibitory effect was abolished, while the stimulatory effect became much more pronounced. We suggest that the effects of sigma receptor ligands are mediated via two receptor subtypes, one stimulatory and the other inhibitory, and only the inhibitory subtype is subject to desensitization.

Mechanisms of cardiopulmonary resuscitation in a patient with right ventricular dilatation--an echocardiographic contribution

The mechanism of cardiopulmonary resuscitation is still debated. Two different theories have been proposed: direct cardiac compression versus intrathoracic pressure. A patient with dilated right cardiac chambers, who underwent a transesophageal echocardiography study during cardiopulmonary resuscitation, is reported. The direct compression mechanism was clearly demonstrated.

Influence of coronary angioplasty on the progression of coronary atherosclerosis

This study examines the effect of coronary angioplasty on the progression and appearance of new disease in sites of the coronary tree that were not dilated by the balloon. We examined 355 pairs of coronary angiograms from 252 patients. The study consisted of consecutive patients who were referred for catheterization > 1 month after successful angioplasty. Progression/regression and the appearance of new narrowings at sites not dilated by angioplasty were determined. The life-table method was used to determine outcome, and any event (progression, regression, and new narrowing) was analyzed according to the time of occurrence. The angioplasty artery was compared with the non-angioplasty artery and the effect of restenosis was determined by comparing arteries with and without restenosis. Progression/regression rates were not significantly different in angioplasty and non-angioplasty arteries. More new narrowings were identified in the angioplasty artery (p < 0.01). With regard to narrowings located in the angioplasty artery, progression was more common, regression less common, and the appearance of new narrowings more common in arteries with restenosis than in non-angioplasty arteries or arteries without restenosis. We believe that mechanical trauma to the artery during angioplasty could accelerate disease progression and the appearance of new narrowings in angioplasty arteries, whereas normalization of flow rate and pattern, especially in arteries without restenosis, attenuates the rate of progression and the appearance of new narrowings in these arteries. The final outcome depends on the balance between these factors.

Inotropic action of sigma receptor ligands in isolated cardiac myocytes from adult rats

High affinity binding sites for sigma receptor ligands were found in membranes of cardiac myocytes from adult rats. The sigma receptor ligand (+)-3-hydroxyphenyl-N-(1-propyl)piperidine ((+)-3-PPP) binds with a Kd of 17.9 +/- 4.0 nM and a Bmax of 275 +/- 32.1 fmol/mg protein. Competition experiments of (+)-pentazocine with [3H]1,3-di-O-tolylguanidine ([3H]DTG) binding yielded a Ki of 6.1 +/- 1.3 nM. The majority of the sites (> 80%) were of the sigma 1 subtype. Exposure of isolated cardiomyocytes from adult rats to (+)-3-PPP (10 nM-1.0 microM) caused a marked concentration-dependent increase in the amplitude of systolic cell contraction, reaching 149% of control level, with an apparent ED50 value of 4.5 nM. The increase in the contraction amplitude was markedly inhibited by pretreatment with verapamil or thapsigargin. An increase in the amplitude of [Ca2+]i transients, similar to that in the amplitude of cell contraction, was observed in indo-1-loaded cardiomyocytes exposed to 0.1 microM (+)-3-PPP. Exposure to 10 nM of haloperidol or (+)-pentazocine induced an increase in the amplitude of contraction, reaching 188% and 138% (respectively) of control level. A lower concentration of haloperidol or (+)-pentazocine (1 nM) did not induce an increase in the contraction amplitude but rather reduced the amplitude to 70-80% of control.

Percutaneous Transluminal Coronary Angioplasty in Octogenarians

Revascularization is a theoretically ideal technique for treating repeated angina pectoris in elderly patients. Coronary angioplasty is an attractive option if it can be performed safely. In this report, we describe our experience with 80 angioplastic procedures in 72 patients older than 80 years. Seventy-two of these procedures (90%) were performed after 1990 using the currently available, improved angioplasty equipment. A third of these patients did not have any risk factors for coronary artery disease and 45% had only 1 risk factor. A history of previous myocardial infarction or coronary bypass surgery was present in 48 (67%) patients. In most patients (72%), angioplasty was performed during an admission for unstable angina or acute myocardial infarction. Single-vessel disease was present in 22% of patients. Successful angioplasty was performed in 92% of patients and major complications occurred in 8% of patients. Four patients (6%) died; in all of them, angioplasty was performed emergently to treat cardiogenic shock. None of 68 patients who underwent elective angioplasty for stable angina or a semielective procedure for unstable angina died during the hospitalization. We conclude that angioplasty can be performed safely in the carefully selected octogenarian. There is a low-risk subgroup of patients with limited disease in whom angioplasty is an attractive treatment strategy.

Permanent Cardiac Pacing in Octogenarians

A significant percentage of patients in need of a permanent pacemaker are older than 80 years. The implantation policy may be determined either by the patient's physical activity or by chronologic age. The trend in pacemaker implantation in patients over 80 during the last 10 years in our institution was evaluated and compared with the trend in the patients younger than 80 at the time of implantation. Of 519 patients who had primary pacemaker implantation, 152 (29%) were older than 80 at the time of the procedure. Another 189 patients had second implantation procedures, and 80% of them were older than 80 years. Complete atrioventricular block was the indication for pacing in 44 Â+/- 11% and sick sinus syndrome in 25 Â+/- 7%. The tendency to implant dual-chamber pacemakers increased from 0% during 1985 to 76% in 1994, including 69% DDD and 31% DDDR, but the transition was faster in the younger group. By 1994, there was no difference in the incidence of advanced pacing systems in the 2 age groups. During 1985, only VVI pacemakers were replaced, and during 1994, less than 10% were replaced with simple ventricular pacing units. Pacing system upgrading was frequent during the second half of the decade. The success and complication rate of implantation did not differ in the 2 groups.

Combined mechanical and thrombolytic treatment for totally occluded bypass grafts

Totally occluded venous grafts are usually less amenable to mechanical reperfusion alone (for example percutaneous transluminal coronary angioplasty, PTCA) because of the large mass of thrombotic material within the graft. A combined approach using mechanical and thrombolytic treatment might therefore be more successful. Twenty one patients (20 males, one female) with a mean age of 64.5 (SD 5.6) years underwent angiography because of crescendo or unstable angina (n = 19) or myocardial infarction (n = 2) at a mean of 21.7 (18.6) days after onset of symptoms (range 1-60). All patients had had coronary artery bypass grafting (CABG) at a mean of 8.02 (4.02) years (range 0.3-13 years) before the current admission. At catheterisation, totally occluded venous bypass grafts to the left anterior descending coronary artery or diagonal (n = 10), marginal (n = 6), or right coronary artery (n = 5) were found. A combination of PTCA and thrombolytic treatment (in eight patients extended thrombolysis for 24 hours) was successful in reopening the venous graft in 16/21 patients (76.2%). Immediate complications included femoral haematoma (4), distal embolisation (3), and infection in one patient. Out of 13 patients catheterised within three months, two had reoccluded, seven had restenosis, while four had patent grafts. Recurrent PTCA (at least once more) was done in eight patients. At long term follow up of a mean of 26.7 (21.6) months (range 4-75 months), four patients were asymptomatic, eight still suffered from mild stable angina, while three had recurrent hospital admissions and needed a second coronary artery bypass. A combination of thrombolytic treatment and PTCA is a feasible and practised approach to recanalise recently occluded venous bypass grafts.

Comparison of early invasive and conservative treatments in patients with anterior wall non-Q-wave acute myocardial infarction

To compare the long-term prognosis of a group of patients treated by an early invasive approach after a non-Q-wave anterior wall acute myocardial infarction (AMI) with a similar group treated conservatively, data from 110 consecutive patients with non-Q-wave AMI were retrospectively obtained from 3 different hospitals: (1) a hospital with coronary angioplasty and coronary bypass facilities favoring on early invasive approach, (2) a hospital with a catheterization laboratory and no coronary angioplasty or coronary bypass facilities, and (3) a community hospital without a catheterization laboratory. Patients were divided according to the presence or absence of an early invasive approach: those who had undergone in-hospital catheterization and revascularization (n = 55) and those with a conservative approach (n = 55). The early invasive approach resulted in a significant decrease in major events. The rate of recurrent myocardial infarction was 29% in the conservative group versus 7.2% in the invasive group (p = 0.025). Survival rate curves at 3-year follow-up showed significant differences in mortality (p = 0.001), recurrent myocardial infarction (p = 0.002), recurrent angina pectoris (p = 0.001), and development of congestive heart failure (p = 0.05). Multivariate analysis disclosed the early invasive approach to be an independent predictor for decreasing the likelihood of recurrent infarction by 86% (odds ratio 0.14, confidence intervals 0.04 to 0.48, p = 0.0006), and for decreasing the likelihood of recurrent angina by 66% (odds ratio 0.34, confidence intervals 0.18 to 0.63, p < 0.005). The early invasive strategy may result in an improved outcome in the treatment of patients with non-Q-wave anterior wall AMI compared with patients treated conservatively.

Early intravenous thrombolysis in acute myocardial infarction: the Jerusalem experience

Myocardial damage in acute myocardial infarction is a time-dependent process. We examined the influence of very early thrombolytic therapy, comparing prehospital to hospital administration, in a consecutive group of patients with myocardial infarction on mortality, complications and the preservation of left ventricular function. Seven hundred sixty patients received early thrombolytic therapy: 114 at home (time delay to treatment 1.4 +/- 0.8 h) and 646 in hospital (2.1 +/- 1.0 h). Sixteen patients died in hospital and significant hemorrhage occurred in 15 (including three patients with hemorrhagic stroke). There was no difference between groups in hospital mortality or rate of complications. The duration of ischemia was shorter in patients with prehospital therapy (pain duration: 3.3 +/- 2.1 vs. 4.0 +/- 2.2; P < 0.05, and time to recovery of the ST segment in the electrocardiogram: 4.3 +/- 3.3 vs. 6.6 +/- 6.3; P < 0.002). Peak plasma creatine kinase was earlier in patients with prehospital therapy (11.2 +/- 5.0 vs. 13.0 +/- 5.8; P < 0.002), although there was no difference between groups in the absolute peak plasma level. Left ventricular function was assessed by contrast ventriculography 1 week after admission (616 patients). Ventricular function was better in patients with prehospital therapy: (ejection fraction of 58 +/- 13% vs. 54 +/- 15%; P < 0.05 and a left ventricular dysfunction index of 534 +/- 515 vs. 691 +/- 519 units; P < 0.05). We conclude that prehospital thrombolytic therapy is feasible and safe. Reperfusion is achieved earlier and more myocardium can be salvaged using this strategy without increasing the rate of complications.

[Angioplasty for vein grafts and native coronary arteries after previous coronary artery bypass grafting]

219 patients after previous coronary artery bypass grafting (CABG) underwent coronary artery or vein graft angioplasty in 1984-1991. 452 stenotic lesions out of 498 were successfully dilated in 337 procedures (90.7%). For arterial lesions the initial success rate had been 89.2% (321/360) and for vein graft lesions 94.9% (131/138). For repeated angioplasty the success rate was the same. Major complications included 3 deaths (0.9%). 15 myocardial infarctions (5.3%) and 1 emergency CABG. Factors that had reduced the success rate were lesions at the proximal anastomosis, total occlusions, and complex (type C) lesions. Time since grafting did not affect success rate of the second procedure. Restenosis after successful angioplasty was 37.3% (34/91) for arterial lesions and 56.8% (25/44) for graft lesions, after a mean time of 11.2 +/- 2.7 months. Restenosis was more common in type C lesions and old vein grafts. There was considerable improvement in treadmill exercise time of patients after the angioplasty (5.92 vs 7.31 minutes) and in double product. During a follow up of about 3 years, 7.6% (15/196) died of cardiac events, 5.2% (10/189) had myocardial infarctions, 10.5% (20/189) were reoperated and 31.0% (68/219) needed at least 1 repeat angioplasty. Long term followup was better after angioplasty of native arteries than of grafts. After angioplasty of vein grafts, there were more cardiac related deaths, more MIs and more reoperations than after angioplasty of native arteries: 11.5% vs 3.5%, 9.6% vs 2.8%, 21% vs 4.9%, respectively, than in the arterial group. Considering the high mortality and morbidity of reoperation, balloon angioplasty in selected patients may be the preferred strategy. Clinical and angiographic results are better after re-angioplasty of native arteries than vein grafts.

Transradial approach for coronary angiography and angioplasty

The transradial approach has currently been advocated as an alternative catheterization method for coronary angiography and angioplasty, due to the recent miniaturization of angioplasty equipment. The purpose of this study was to assess the practical clinical applicability of this method. From June to November 1994, 100 patients underwent coronary angiography and angioplasty with the transradial approach. Their mean age was 66.6 +/- 11.2 years, and 79 were men. In 4, radial puncture was not successful, and in 3, femoral access was necessary to complete the procedure. Coronary angioplasty was performed in 63 patients (76 lesions) with angiographic success (per lesion) of 96%. In 5 patients, a stent was successfully implanted. All patients were ambulatory on the day after the angioplasty procedure. In 98% of the patients, the introducer was taken out 1 to 4 hours after the procedure by local compression using a special custom-made device. No patient required blood transfusion. Major complications occurred in 2 patients; both had a cerebrovascular accident (1 probably not procedure-related), and both recovered. A radial pulse was palpated in 91 of the patients before discharge, and in 6 others, adequate flow could be heard with Doppler. In 2 patients, radial flow was restored within several weeks. None of the patients suffered from ischemia of the hand. Two patients had a small pseudoaneurysm successfully treated by local compression. Thus, coronary angioplasty can be performed safely using the transradial approach with relatively few vascular complications and with better patient comfort. However, the procedure is more time-consuming initially compared with the transfemoral approach due to a learning curve regarding equipment selection and catheter manipulation.

Retrieval of occluding unexpanded Palmaz-Schatz stent from a saphenous aorto-coronary vein graft

The Palmaz-Schatz coronary stent is used frequently to reduce the rate of restenosis of balloon angioplasty in saphenous vein grafts. In many European centers, the stent, manually crimped on a balloon, is advanced across the stenosis without a protective sheath. This report describes a patient in whom an attempt to deploy a stent in the orifice of a saphenous vein graft was complicated by dislodgement of the unexpanded stent from the balloon. The unexpanded stent caused immediate occlusion of the vein graft and severe ischemic symptoms. The stent was retrieved by inflation of another balloon in the graft, distal to the stent, pulling the balloon toward the guiding catheter, and then withdrawing the whole system.

Aorto-atrial fistula following internal jugular vein catheterization

A 48-year-old woman with giant haemangioma of the liver underwent percutaneous transjugular placement of a stent in the left hepatic vein for relief of an obstruction due to the compression of the benign liver tumour. Following the procedure, paroxysmal atrial fibrillation occurred and right-sided heart failure gradually appeared. Echocardiography and cardiac catheterization demonstrated a fistula between the aortic root and the right atrium, that was confirmed on surgery.

The effect of cytotoxic lymphocytes on contraction, action potential and calcium handling in cultured myocardial cells

Cytotoxic T lymphocytes are important in the pathogenesis of several disease states, yet the pathophysiology of the lymphocyte-myocyte interaction is not well known. We have developed in vitro viral and autoimmune models to study the physiological phenomena associated with this interaction. To produce these models, lymphocytes were obtained from adult rats injected either with mengo virus or autologous cardiac myocytes. Cardiac myocytes from neonatal rats were then exposed to these lymphocytes. In both models, reversible physiologic changes in myocytes preceded irreversible cell damage. The physiologic changes included reduced amplitude of myocyte contraction, impairment of relaxation and prolongation of the duration of contraction and action potential. In addition, oscillations were noted in the plateau phase of the action potentials. These physiologic changes were accompanied by an early elevation in the cytosolic free calcium concentration, a late elevation in the total exchangeable calcium pool, and attenuation of the [Ca2+]i transient signals. Verapamil inhibited the late elevation in the total exchangeable calcium pool, but failed to inhibit the early elevation in the cytosolic free calcium concentration. These phenomena may explain transient cardiac functional abnormalities that may appear during myocarditis prior to cell destruction.

One-stage coronary angiography and angioplasty

The combination of diagnostic angiography and angioplasty as a single procedure is becoming common practice in many institutions, but the feasibility and safety of this strategy have not been reported. This report describes 2,069 patients who underwent coronary angioplasty over a 3-year period at an institution where combined angiography and angioplasty is the norm. All patients were prepared before angiography for potential immediate angioplasty. In 1,719 patients, angioplasty was performed immediately after the diagnostic angiogram, while separate procedures were performed in 350 patients. Of those 350 patients, 254 were referred for angioplasty after diagnostic angiography at other hospitals. One thousand one hundred ninety-seven patients were admitted electively for treatment of stable angina pectoris, and 872 underwent procedures during hospitalization for unstable angina or acute myocardial infarction. One thousand nine hundred seven patients (92.2%) had successful angioplasties; in 130 patients (6.3%) the lesion could not be dilated, but no complication occurred, and in 32 patients (1.5%) angioplasty ended with a major complication (0.8% death, 1.0% Q-wave myocardial infarction, 0.5% emergency coronary artery bypass surgery). There was no difference between the combined and staged groups with regard to success, major and minor complication rates or in length of hospitalization after angioplasty. We conclude that routine combined strategy for angiography and angioplasty is feasible, safe, easier for the patient, and more cost-effective than 2 separate procedures.

Sigma receptor ligands modulate contractility, Ca++ influx and beating rate in cultured cardiac myocytes

Specific binding of [3H]-1,3-di-o-tolylguanidine (DTG) and (+)-[3H]-(3-hydroxyphenyl)-N-(1-propyl)-piperidine [(+)-3-PPP] to membranes of cultured cardiac myocytes from neonatal rats revealed the presence of sigma receptors on these cells. Exposure of cultured cardiomyocytes to nanomolar concentrations of (+)-3-PPP, (+)-pentazocine and haloperidol induced specific patterns of changes in contractility of electrically paced cultures. The amplitude of systolic cell-motion (ASM) decreased by 10 to 25% 1 to 2 min after drug addition, then transiently increased (3-10 min) and finally decreased to about 75% of control level. Fluorescence measurements on indo-1 loaded cardiomyocytes revealed drug-induced changes in the size of the concentration of free cytosolic calcium ([Ca++]i)-transients, similar to the changes observed in ASM. These changes appear to be mediated by corresponding changes in the rates of 45Ca++ influx which increased 2 to 7 min after the addition of (+)-3-PPP and decrease to 50% of the control level thereafter. Preincubation with thapsigargin, which depletes the sarcoplasmic reticulum-Ca++ stores, did not affect the pattern of changes in ASM, induced by the subsequent addition of (+)-3-PPP. This indicates that the changes in [Ca++]i are not mediated by sarcoplasmic reticulum-Ca++ transport systems. Exposure to sigma ligands did not affect the apparent sensitivity of the myofilaments to Ca++, as indicated by the relationships between changes in ASM and in [Ca++]i-transients. Cultures which were not paced, contracted spontaneously at a constant rhythm. Sigma receptor ligands caused changes in beating frequencies which were followed by irregular contractions.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of quinidine and myocardial ischemia on the isolated rat heart with fat-free diet

Fat-free diet changes the lipid content and the electrophysiological properties of the rat myocardium. Five percent fat supplementation to the diet does not alter the basic electrophysiological properties but still has a biochemical effect on the lipid content of the myocardium. The purpose of this work was to determine whether these biochemical alterations affect the response of the myocardium to quinidine and ischemia, both of which interact with the lipid component of the membrane. We used strength-duration, strength-interval and threshold of ventricular fibrillation to measure the electrophysiological properties of the isolated rat heart at baseline and after 30 minutes of quinidine perfusion or coronary artery ligation. The fatty acid composition of the myocardium was analyzed. We found that a fat-free diet caused essential fatty-acid deficiency, while 5% fat supplementation had a partial protective effect. Quinidine decreased excitability and increased refractoriness in both groups but had more effect on the fat-free diet hearts group. There was no difference in the ventricular fibrillation threshold. Ischemia increased myocardial excitability in the fat-free diet hearts group and had no effect on refractoriness or ventricular fibrillation threshold. These results support the theory that the lipid composition of the myocardial membrane affects its response to lipophilic drugs and ischemia.

Physiological changes induced in cardiac myocytes by cytotoxic lymphocytes: an autoimmune model

BACKGROUND

cytotoxic lymphocytes are important in the pathogenesis of several disease states, yet, the pathophysiology of lymphocyte-myocyte interaction is not well known.

METHODS AND RESULTS

We have developed a model for the in vitro evaluation of autoimmune cytotoxic myocardial damage. Cardiac myocytes were repeatedly injected to adult autologous rats. Following 3 months, histological evidence of myocarditis was seen in 20% of the hearts. Cultured myocytes obtained from newborn rats were exposed to lymphocytes isolated from the immunized animals. Cytotoxic activity was measured using crystal violet staining test. The percentage of killing was increased as the ratio of lymphocytes/myocytes was increased. Verapamil did not block this cytotoxic effect. No killing was seen when myocytes were exposed to non-sensitized lymphocytes. Physiological changes induced in myocytes by cytotoxic lymphocytes were studied. Cell wall motion was measured by an optical method and action potentials with intracellular microelectrodes. Physiological changes observed in myocytes following exposure to cytotoxic lymphocytes included: Impaired relaxation with prolonged contractions, oscillations and prolongation of the plateau of the action potential. Cellular contraction was prolonged up to 4 s before total arrest of spontaneous activity. Verapamil but not tetrodotoxin restored action potentials and contractions to normal. Supernatant collected from cultures of myocytes and lymphocytes had the same effect on myocytes contractility as observed following exposure of myocytes to cytotoxic lymphocytes.

CONCLUSIONS

This supports our hypothesis that these physiological alterations observed in myocytes are mediated by a soluble factor secreted by cytotoxic lymphocytes.

Coronary artery-pulmonary artery fistula associated with hypertrophic cardiomyopathy

This report describes two patients with the combination of a coronary artery fistula from the left anterior descending artery (LAD) to the pulmonary artery together with hypertrophic cardiomyopathy.

Total coronary artery occlusion late after successful coronary angioplasty of moderately severe lesions: incidence and clinical manifestations

Coronary restenosis after balloon angioplasty is a slow process that develops over a few months. In some patients, with an initially successful angioplasty, an artery that originally had only moderate stenosis becomes totally occluded as a result of restenosis. This report describes 16 such patients out of 415 dilated lesions with late angiographic follow-up. Ten patients presented with stable angina pectoris, 5 had unstable angina and only one was admitted with a small myocardial infarction. Visible collaterals were present in 15 patients. Except for the patient who sustained myocardial infarction, none of the late angiograms showed the typical morphological features of acute lesion. We conclude that total coronary occlusion late after successful angioplasty of an artery that was moderately narrowed is rare. The 'restenotic' occlusion is a slow process that stimulates collateral formation and thus the risk of myocardial infarction is small.

Very early thrombolysis in acute myocardial infarction--a light at the end of the tunnel

Myocardial damage in acute myocardial infarction is a time-dependent process. Thrombolytic therapy effectively opens the coronary artery, restores coronary blood flow and prevents ongoing necrosis. We examined the effect of very early thrombolytic therapy (including prehospital administration) in a consecutive group of 510 patients with myocardial infarction on the following factors: mortality, complications and the preservation of left ventricular function. The treatment was given to 89 at home (time delay to treatment 1.2 +/- 0.6 h) and 421 in hospital (2.0 +/- 1.0 h). Twelve patients died in hospital and major hemorrhage occurred in 10. The arterial patency rate in 416 patients who underwent coronary angiography 6 days later was 82%. Infarct size measured by left ventriculography was determined by the area at risk, the delay time until the initiation of thrombolytic therapy, the total duration of ischemic pain and the degree of restoration of arterial blood flow. We conclude that early thrombolytic therapy, particularly prehospital management, is feasible and safe and reduces infarct size and mortality. A further decrease in the delay to initiation of treatment and more effective thrombolytic therapy will further decrease mortality and myocardial damage.

Heat acclimation improves cardiac mechanics and metabolic performance during ischemia and reperfusion

Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of heat-acclimated (AC) rats (at 34 degrees C for 1 mo) and their age-matched controls (C). Diastolic and systolic pressures, coronary flow, and the appearance of ischemic contracture (IC) were measured during progressive graded ischemia, total ischemia (TI), and reperfusion. ATP, phosphocreatine, and intracellular pH were measured during TI and reperfusion with the use of 31P-nuclear magnetic resonance spectroscopy. Systolic pressure was greater in AC hearts than in C hearts (P < 0.0001). During 50% of perfusion pressure 15 and 46% of AC and C hearts, respectively, showed IC (P < 0.001). During 25% of perfusion pressure 85% of the hearts in both groups developed IC. The onset of IC in AC hearts was delayed compared with in C hearts. On reperfusion 93 and 66% of AC and C hearts, respectively, resumed contraction. Recovery of diastolic pressure was 78 and 36% for the AC and C hearts, respectively (P < 0.05). During TI ATP declined by 0.94 and 1.20 mumol/min in AC and C hearts, respectively, resulting in 21 +/- 2.8% preservation of the ATP pool in AC hearts after 30 min of TI (P < 0.001). The AC group also showed a delayed decline in intracellular pH (P < 0.001). The data suggest beneficial effects of heat acclimation on the heart, which were exhibited by greater pressure generation and by the emergence of protecting features during ischemia and reperfusion, possibly via energy-sparing mechanisms.