A small dose of apomorphine counteracts the deleterious effects of middle cerebral artery occlusion in different models.

The present manuscript investigates in two animal species by using two different experimental models of middle cerebral artery occlusion (permanent and transient), the neuroprotective effects of the dopamine receptor agonist apomorphine. These effects were evaluated by measuring the infarct volume and by counting muscle strength at different time points following the ischemic insult. Apomorphine at the dose of 3 mg/Kg when adminsitered at two hours following the occlusion of the middle cerebral artery was able to reduce significantly the infarct volume in the cortex of mice and the ischemic volume of the basal ganglia perfused by the perforant branches of the middle cerebral artery in the rat. In this latter case the behavioral evaluation (i.e. muscle strength) was preserved most effectively in the contralateral side at 24 and 72 hours. The present findings contribute to foster the concept that DA agonists might be useful in the treatment of cerebral ischemia. At the same time the behavioral improvement induced by DA administration following basal ganglia ischemia may be interpreted as the effects of an authentic disease modifying effect rather than a simple symtomatic relief due to a potential loss of DA containing axons in the basal ganglia. These data add on previous evidence showing analogous effects induced by the DA precursor L-DOPA. Apart from providing an evidence of a neuroprotective effect induced by increased DA stimulation the present data call for further studies aimed at comparing the effects of apomorphine with other DA agonists. In fact the quinoline moiety of apomorphine was claimed to protect neurons from a variety of insults independently from a DA agonist activity. The induction of protein clearing pathways appears to be potentially relevant for these effects.

History of allergy is a predictor of adverse events in unstable angina treated with coronary angioplasty.

BACKGROUND: The aim was to investigate prognostic relevance of history of allergy in subjects with unstable angina treated with coronary angioplasty. METHODS: Fifty-seven consecutive patients with unstable angina who underwent coronary angioplasty were enrolled in the study and were divided into two groups: those with a history of allergy (Group A, N = 15); and controls (Group C, N =42). Major adverse cardiac events were recorded over a six-month follow-up period. Patients with primary or unsuccessful angioplasty and patients treated with drug eluting stent were excluded from the study. RESULTS: Group A patients (history of allergy) showed a 46.67% incidence of major adverse cardiac events at six-month follow-up (vs. 9.52% Group C, p < 0.01): results remained significant even in a multiple Cox regression analysis (hazard ratio 7.17, 95% CI 1.71-29.98, p < 0.01). CONCLUSION: History of allergy is an independent predictor of major adverse cardiac events after coronary angioplasty in a six-month follow-up period in unstable angina.

Functional and structural abnormalities in patients with dilated cardiomyopathy.

Passive diastolic properties of the left ventricle were determined in 10 control subjects and 12 patients with dilated cardiomyopathy. Simultaneous left ventricular angiography and high fidelity pressure measurements were performed in all patients. Left ventricular chamber stiffness was calculated from left ventricular pressure-volume and myocardial stiffness from left ventricular stress-strain relations with use of a viscoelastic model. Patients with dilated cardiomyopathy were classified into two groups according to the diastolic constant of myocardial stiffness (beta). Group 1 consisted of seven patients with a normal constant of myocardial stiffness less than or equal to 9.6 (normal range 2.2 to 9.6) and group 2 of 5 patients with a beta greater than 9.6. Structural abnormalities (percent interstitial fibrosis, fibrous content) in patients with dilated cardiomyopathy were assessed by morphometry from right ventricular endomyocardial biopsies. Heart rate was similar in the three groups. Left ventricular end-diastolic pressure was significantly greater in patients with cardiomyopathy (18 mm Hg in group 1 and 22 mm Hg in group 2) than in the control patients (10 mm Hg). Left ventricular ejection fraction was significantly lower in groups 1 (37%) and 2 (36%) than in the control patients (66%). Left ventricular muscle mass index was significantly increased in both groups with cardiomyopathy. The constant of chamber stiffness (beta*) was slightly although not significantly greater in groups 1 and 2 (0.58 and 0.58, respectively) than in the control group (0.35). The constant of myocardial stiffness beta was normal in group 1 (7.0; control group 6.9, p = NS) but was significantly increased in group 2 (23.5). Interstitial fibrosis was 19% in group 1 and 43% (p less than 0.001) in group 2 (normal less than or equal to 10%). There was an exponential relation between both diastolic constant of myocardial stiffness (beta) and interstitial fibrosis (IF) (r = 0.95; p less than 0.001) and beta and fibrous content divided by end-diastolic volume index (r = 0.93; p less than 0.001). It is concluded that myocardial stiffness can be normal in patients with dilated cardiomyopathy despite severely depressed systolic function. Structural alterations of the myocardium with increased amounts of fibrous tissues are probably responsible for the observed changes in passive elastic properties of the myocardium in patients with dilated cardiomyopathy. The constant of myocardial stiffness (beta) helps to identify patients with severe structural alterations (group 2), representing possibly a more advanced stage of the disease.

High pressure assisted coronary stent implantation accomplished without intravascular ultrasound guidance and subsequent anticoagulation.

OBJECTIVES: The purpose of this study was to determine the efficacy of treatment with antiplatelet therapy and no anticoagulation after high pressure assisted coronary stent implantation performed without intravascular ultrasound (IVUS) guidance. BACKGROUND: Previous studies have shown that during IVUS-guided Palmaz-Schatz coronary stenting, it is safe to withhold anticoagulation when stent expansion has been optimized by high pressure balloon dilation. METHODS: Patients that had successful coronary stenting without IVUS guidance were treated with ticlopidine, 500 mg/day, and aspirin, 325 mg/day, for 1 month and then received only aspirin, 325 mg/day, indefinitely. Patients were not treated with warfarin (Coumadin) or heparin after successful stenting. Clinical and angiographic events were assessed at 1 month. RESULTS: A total of 201 intracoronary stents were implanted in 127 patients with 137 lesions. The average number of stents per lesion was 1.4 +/- 0.8, and the average number of stents per patient was 1.6 +/- 1.1. Stent deployment was performed for elective indications in 79% of procedures and for emergency indications in 21%. There were four stent thrombosis events for a per patient event rate of 3.1% and a per lesion event rate of 2.9%. CONCLUSIONS: After high pressure assisted stenting performed without IVUS guidance, there was an acceptable incidence of 3.1% of stent thrombosis with the combination of short-term ticlopidine and aspirin therapy and no anticoagulation. Although the study involved only 127 patients, the results support the relative safety of stenting without IVUS guidance and with antiplatelet therapy only in comparison to historical trials on stenting performed with postprocedure anticoagulation.

Is there coronary vasoconstriction after intracoronary beta-adrenergic blockade in patients with coronary artery disease.

Vasomotility of normal and stenosed coronary arteries was studied at rest and during supine bicycle exercise in 10 patients with classical exercise-induced angina pectoris receiving 1 mg intracoronary propranolol before the exercise test (propranolol group). Normal and stenotic coronary lumen areas were determined from biplane coronary arteriograms using a computer-assisted system. Measurements were performed at rest, after 1 mg intracoronary propranolol, during supine exercise (89 W for 3.4 minutes) and 5 minutes after 1.6 mg sublingual nitroglycerin administered at the end of the exercise test. The results were compared with previously obtained data on the effect of dynamic exercise on coronary lumen area in 12 patients receiving no medication (control group) and in 6 patients receiving 0.1 mg intracoronary nitroglycerin before the exercise test (nitroglycerin group). In the control group, coronary stenosis area decreased during exercise to 71% of levels at rest (p less than 0.001) whereas normal coronary lumen area increased to 123% of control (p less than 0.01). In the propranolol group both normal (113%, p less than 0.05 versus rest) and stenotic coronary lumen area (122%, p less than 0.05 versus rest) increased during exercise. A similar increase in both normal and stenotic areas was observed during exercise after pretreatment with 0.1 mg intracoronary nitroglycerin (123%, p less than 0.01 and 114%, p = NS versus rest). Sublingual administration of 1.6 mg nitroglycerin at the end of exercise increased coronary stenosis area to 145% (p less than 0.01 versus rest) in the propranolol group and to 115% in the control group (p = NS versus rest). It is concluded that intracoronary administration of propranolol does not potentiate coronary vasoconstriction of the epicardial vessels at rest and during exercise. In contrast, intracoronary propranolol prevents exercise-induced stenosis narrowing either because of reduced myocardial oxygen demand with a lower coronary blood flow resulting in a smaller transstenotic pressure gradient and, thus, a smaller flow-induced fall in stenosis distending pressure; or because of "local" beta-receptor blockade with unopposed distal arteriolar alpha-receptor tone, resulting in a higher poststenotic pressure and, thus, in a greater stenosis distending pressure; or because of a local anesthetic effect of propranolol with a decrease in calcium influx to the coronary smooth musculature.

Clinical and angiographic outcome after Palmaz-Schatz stent implantation guided by intravascular ultrasound.

Intracoronary stents can be implanted with a low incidence of stent thrombosis (< 1%) when the stent procedure is guided by intravascular ultrasound. The long-term clinical and angiographic effects, however, have not been reported. This study assesses the 6 month clinical and angiographic results of a consecutive series of patients with intravascular ultrasound guided Palmaz-Schatz stent deployment that were not treated with subsequent anticoagulation after a successful stent implantation procedure. From March, 1993 to April 1994, 411 patients underwent Palmaz-Schatz stent implantation. There were 26 patients that had uncomplicated Palmaz-Schatz stent implantation that were treated with a standard anticoagulation regimen that are not evaluated in this study. Thus, this study includes an assessment of 385 patients that had either a successful intravascular ultrasound guided stent implantation procedure and did not receive post procedure anticoagulation or had a procedural complication. Procedural success was achieved in 369 patients (96%). Clinical success (procedure success without early post procedure event) was achieved in 363 patients (94%). There were 2 acute stent thrombosis events (0.5%) and 1 subacute stent thrombosis (0.3%) in the group of 369 patients with 454 lesions treated without anticoagulation. At 6 month clinical follow-up the incidence of myocardial infarction was 4.9% and the rate of coronary bypass surgery was 6.2%. There was a 2.1% incidence of death. Emergency intervention (emergency angioplasty or bailout stent implantation was necessary in 3 patients (0.8%). The total incidence of repeat percutaneous intervention was 11.4%. By 6 months clinical follow-up, major events had occurred in 19.2% of patients. The angiographic lesion restenosis rate, according to 50% diameter stenosis criteria, was 19%. The incidence of restenosis per patient was 22%. In conclusion, intravascular ultrasound guided Palmaz-Schatz can be performed without subsequent anticoagulation with a low incidence of stent thrombosis and acceptable clinical and angiographic outcome at 6 month clinical follow-up.

"Kissing" stents for bifurcational coronary lesion.

The coronary stents implantation into each vessel of a bifurcational lesion ("kissing" stents) in two patients is reported. The first patient had two short "kissing" stents implanted in an ostial lesion of the left anterior descending and the intermediate branch. The second patient had successful "kissing" stents implantation in the bifurcational lesion of the left main coronary artery.

[Evaluation of the ejection fraction using 2 simplified echocardiographic methods in patients with ischemic heart disease and left ventricular asynergy]. / Valutazione della frazione d'eiezione mediante due metodi ecocardiografici semplificati in pazienti con cardiopatia ischemica e asinergie ventricolari sinistre.

UNLABELLED: This study was undertaken to assess the reliability of two simplified echocardiographic methods (Method A and B) in evaluating ejection fraction (E.F.) in patients with left ventricular wall motion abnormalities (WMA). Method A was obtained with a microprocessor that allows the superimposition of a calibrated ellipse to left ventricular end-diastolic and end-systolic silhouettes; the shape of the ellipse was modified to obtain the best superimposition of the ellipse outline to the endocardium. E.F. was then obtained with the formula: VD-VS/VD where VD and VS were the ellipse volumes at end-diastole and end-systole. In method B E.F. was obtained averaging 3 regional E.F. obtained with a longitudinal axis and 3 different transverse diameters. In a group of 40 patients with WMA and excellent 2D echo images the correlation between echocardiographic and angiographic values was r = 0.76 for method A and r = 0.92 for method B. Method B was also tested in a group of 25 consecutive unselected patients with left ventricular WMA; in this group the correlation with angiographic values of E.F. was r = 0.84. IN CONCLUSION: in patients with WMA method B must be preferred because it is easier to perform and presents a better correlation with angiographic data than method A.

Coronary tandem lesions: effect of exercise.

Coronary vasomotion of two stenoses in series (i.e., tandem lesion) was studied in 10 patients with coronary artery disease. Percent area stenosis was 69% +/- 23% for the first (S1) lesion and 70% +/- 37% for the second (S2). Quantitative coronary arteriography was carried out at rest, during two levels of exercise (2 minutes, 75 W and 1.9 minutes, 100 W), and at 5 minutes after sublingual administration of 1.6 mg nitroglycerin. Both stenoses showed exercise-induced vasoconstriction (S1: -29%, p less than 0.01 versus rest; S2: -29%, p less than 0.01 versus rest), which was reversible after sublingual administration of nitroglycerin (S1: +15%, not significant versus rest; S2: +13%, not significant versus rest). The vessel segment between the two stenoses showed no vasomotion during exercise, whereas the pre- and poststenotic "normal" vessel segment elicited exercise-induced vasodilation. There was an inverse relationship between percent area stenosis of the second lesion and exercise-induced vasoconstriction of the first lesion (correlation coefficient = 0.84). The more severe the distal stenosis was, the less exercise-induced stenosis narrowing of the proximal lesion was observed. Thus it is concluded that coronary vasomotion of two stenoses in series is dependent on both active and passive mechanisms because both lesions show exercise-induced vasoconstriction, but vasomotion of the proximal lesion is dependent on the severity of the second one.

Integrated ultrasound evaluation of dissecting aneurysm of the aorta by the combined use of transesophageal echocardiography and intravascular ultrasound.

In order to obtain complete ultrasound imaging of the entire aorta, transesophageal echocardiography and intravascular ultrasound were performed on 3 patients with acute (2 cases) or chronic (1 case) aortic dissection. In each case the integrated use of transesophageal echocardiography and intravascular ultrasound provided an accurate evaluation of the dissection and of its anatomic extension.

[Invasive hemodynamic assessment and interventional therapy]. / Valutazione emodinamica invasiva e terapia interventistica.

Cardiovascular diseases are the main reason for hospitalization and usually followed by a conservative therapeutic approach. Due to the improvement over the last few years in the results of surgery in the elderly, the number of hemodynamic studies has increased. Hemodynamic studies are generally performed in elderly patients with symptomatic valvular heart disease and acute myocardial infarction with complications. The incidence of complications in the elderly during catheterization and coronarography is higher than in younger but still low. Cardiovascular hemodynamics in the elderly is determined by a combination of lifestyle, the presence of cardiac diseases that increase in prevalence with advancing age (e.g., coronary artery disease) and age-related changes in cardiovascular hemodynamic per se. With age, the tunica media of major blood vessels stiffens. This produces a elevation of systolic blood pressure (afterload) in many elderly patients which in turn increases left ventricular (LV) wall stress and results in mild compensatory LV hypertrophy. This compensatory hypertrophy normalizes wall stress, but produces pertubations in diastolic function such as: a reduction in the rate of both diastolic and LV peak filling, a diminished diastolic compliance associated with LV hypertrophy and a greater dependence upon left atrial contraction to maintain cardiac output. Recently the proportion of these patients who have percutaneous transluminal coronary angioplasty (PTCA) is growing. PTCA can be performed with a high rate of clinical success. Complete revascularization is low, particularly in patients with trivessel disease. The most common reasons for incomplete revascularization were: vessels with chronic total occlusion and vessels with diffuse disease. The rate of major cardiac complications was high among patients at high-risk in the presence of trivessel disease and low left ejection fraction. Long-term results were encouraging. For 90% of patients who had clinical success after PTCA, the end results continued to be beneficial. In conclusion, PTCA is a valid therapeutic alternative in elderly patients with coronary artery disease. In subsets of patients with single and bivessel disease, the short- and long-term outcome is very favourable. In patients with triple vessel disease, early clinical success rate is low but the long-term success rate is, however, acceptable.

Hemodynamic study of intravenous propionyl-L-carnitine in patients with ischemic heart disease and normal left ventricular function.

Propionyl-L-carnitine was given intravenously to ten patients with chronic ischemic heart disease who had normal left ventricular function and had not had a previous myocardial infarction. Subsequently, pulmonary and systemic circulation, left ventricular function, and the relationship between the ventricle and afterload were evaluated. This drug, at a dose of 15 mg/kg, improves ventricular function by easing the load and by enhancing cardiac efficiency. The ejection impedance is reduced with a consequent increase in stroke volume as a result of a) a decrease in systemic and pulmonary resistance and b) an increase in arterial compliance. Arterial pressure is maintained due to an increase in total external heart power. Since the tension time index shows a proportionally smaller increase in the energy requirement, it follows that cardiac efficiency has been improved and ventricle-afterload matching is optimal. These results suggest but do not prove that propionyl-L-carnitine exhibits a positive inotropic property.

Effect of intracoronary and intravenous propranolol on human coronary arteries.

The effect of intracoronary and intravenous propranolol on coronary vasomotion was evaluated in 28 patients with coronary artery disease. Luminal area of a normal and a stenotic coronary vessel segment was determined at rest, during submaximal bicycle exercise and 5 min after 1.6 mg sublingual nitroglycerin administered at the end of the exercise test involving biplane quantitative coronary arteriography. Patients were divided into three groups: group 1 (n = 12) served as the control group, group 2 consisted of 10 patients with intracoronary administration of 1 mg propranolol and group 3 of six patients with intravenous administration of 0.1 mg kg-1 propranolol prior to the exercise text. In the control group there was coronary vasodilation (+23%, P less than 0.01) of the normal and coronary vasoconstriction (-29%, P less than 0.001) of the stenotic vessel segment during bicycle exercise. After sublingual administration of 1.6 mg nitroglycerin there was vasodilation of normal (+40%, P less than 0.001 vs rest) and stenotic (+12%, NS vs rest) vessel segments. In group 2 intracoronary propranolol was not accompanied by a change in coronary vessel area but both normal (+13%, P less than 0.05) and stenotic (+22%, P less than 0.05) vessel segments showed coronary vasodilation during bicycle exercise. After sublingual nitroglycerin there was further vasodilation of both normal (+31%, P less than 0.001 vs rest) and stenotic (+45%, P less than 0.01 vs rest) arteries. In group 3 intravenous administration of propranolol was associated with a decrease in coronary luminal area of both normal (-24%, P less than 0.001) and stenotic (-31%, P less than 0.001) vessel segments.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of gallopamil on coronary blood flow and vasomotility]. / Effetti del gallopamil sul flusso e sulla vasomotilità coronarica.

Using quantitative coronary arteriography, the luminal area was measured in the proximal, middle and distal third of a normal coronary vessel in basal condition and 15 min after 0.005 mg/Kg ic gallopamil (Group 1); 15 min after ic placebo (Group 2); 15 and 30 min after iv gallopamil at a dose of 0.03 mg/Kg (Group 3A) and 0.05 mg/Kg (Group 3B). A significant (p less than 0.001) vasodilation was observed in all segments in Group 1 and only in distal segment (p less than 0.05) in Group 3B. Neither did the heart rate, systolic blood pressure nor the coronary driving pressure show any changes. In the second section of this study, we analyzed the effects of the drug on coronary blood flow and resistance in 8 patients without clinical and/or objective evidence of coronary artery disease. Using thermodilution technique, the coronary sinus blood flow (CSBF) and coronary resistance (CR) were measured in basal condition and 5, 10, 15 and 30 min after 0.05 mg/Kg iv gallopamil. We observed a significant (p less than 0.001) increase of CSBF after 10 min and a significant decrease of CR after 10 min (p less than 0.001) and 15 min (p less than 0.05). In conclusion, our results suggest that the anti-ischemic effect of gallopamil can be related not only to the reduction of myocardial oxygen requirement, but also to an improvement of coronary blood flow with a decrease in coronary resistance.

Regression of coronary artery dimensions after successful aortic valve replacement.

BACKGROUND: The effect of regression of myocardial hypertrophy on coronary artery dimensions was evaluated in patients with aortic valve disease who underwent valve replacement. METHODS AND RESULTS: Cross-sectional area (CSA) of the three major coronary arteries (left anterior descending [LAD], left circumflex [LCx], and right coronary artery) was determined by quantitative coronary arteriography in 15 patients with aortic valve disease before and 38 months (range, 14-113 months) after successful aortic valve replacement. Twelve normal subjects served as controls. Left ventricular (LV) angiographic mass was calculated according to the method of Rackley. CSA of the left coronary artery was larger in aortic valve disease than in controls (LAD, 15 versus 8 mm2, p less than 0.001; LCx, 14 versus 6 mm2, p less than 0.001). After valve replacement, CSA of the left coronary artery decreased (LAD, 12 mm2, p less than 0.05 versus before surgery; LCx, 11 mm2, p less than 0.05 versus before surgery) but remained significantly larger than in controls. CSA of the right coronary artery in patients with aortic valve disease was not different from controls. LV muscle mass was significantly increased in aortic valve disease patients before (364 g) and after (250 g) valve replacement compared with controls (135 g). The appropriateness of coronary artery size with respect to muscle mass was evaluated by normalizing CSA of the left coronary artery (LAD + LCx) per 100 g of LV muscle mass (mm2/100 g). This index amounted to 11 mm2/100 g in controls, to 8 mm2/100 g in preoperative patients (p less than 0.05 versus controls), and to 10 mm2/100 g in postoperative patients with aortic valve disease (p = NS versus controls). CONCLUSIONS: In patients with aortic valve disease, CSA of the proximal LAD and LCx is increased, but this increase is not sufficient to keep CSA per 100 g of LV mass within normal limits. The postoperative decrease in muscle mass is associated with a decrease in the size of LAD and LCx, whereas the size of the right coronary artery remains unchanged. In contrast to the preoperative state, the residually hypertrophied LV myocardium after aortic valve replacement is supplied by an enlarged but adequately sized LAD and LCx.

Effect of intravenous propranolol on coronary vasomotion at rest and during dynamic exercise in patients with coronary artery disease.

Coronary vasomotion was studied at rest and during bicycle exercise with biplane quantitative coronary arteriography in 28 patients with coronary artery disease. Patients were divided into two groups; the first 18 patients served as controls (group 1), and the next 10 patients were treated with propranolol 0.1 mg/kg, which was infused intravenously before exercise (group 2). Luminal area of a normal and a stenotic vessel segment was determined at rest, during supine bicycle exercise, and 5 minutes after sublingual administration of 1.6 mg nitroglycerin after exercise. In group 1, the normal vessel showed vasodilation (+16%, p less than 0.001) during exercise, whereas the stenotic vessel segment showed vasoconstriction (-31%, p less than 0.001). After sublingual administration of nitroglycerin, there was coronary vasodilation of both normal (+36%, p less than 0.001 vs. rest) and stenotic (+20%, p less than 0.001) vessel segments. Patients with angina pectoris during supine exercise (n = 10) had significantly (p less than 0.05) more vasoconstriction (-36%) than patients without angina (-23%). In group 2, intravenous administration of propranolol at rest was associated with a decrease in luminal area of both normal (-24%, p less than 0.001) and stenotic (-43%, p less than 0.001) vessel segments; however, during subsequent exercise, both normal (-2%, p = NS vs. rest) and stenotic (-3%, p = NS vs. rest) vessel segments dilated when compared with the measurements after propranolol. Administration of nitroglycerin further increased luminal area of both vessel segments (normal segment, +23%, p less than 0.001; stenotic segment, +46%, p less than 0.001 vs. rest). It is concluded that dynamic exercise in patients with coronary artery disease is associated with coronary vasodilation of the normal and vasoconstriction of the stenotic coronary arteries. Patients with exercise-induced angina had significantly more stenosis vasoconstriction than patients without angina although minimal luminal area at rest was similar. Intravenous administration of propranolol is accompanied by a significant decrease in coronary luminal area of both normal and stenotic vessel segments at rest, which is overridden by dynamic exercise and sublingual nitroglycerin. The reduction in myocardial oxygen consumption and the prevention of exercise-induced stenosis vasoconstriction might explain the beneficial effect of beta-blocker treatment in most patients with coronary artery disease.

Coronary vasomotion and coronary flow reserve during exercise.

Coronary vasomotion and coronary blood flow are important determinants of myocardial perfusion in patients with coronary artery disease. New digital angiographic techniques allow to study, not only the dimensions of a stenotic lesion (quantitative coronary arteriography), but also coronary flow reserve (parametric imaging). In a preliminary study both techniques were combined and coronary dimensions, as well as coronary flow reserve were determined in 15 patients (seven normals and eight patients with coronary artery disease) at rest, 45 s after 10 mg i.c. papaverine, during two levels of supine bicycle exercise, as well as 5 min after 1.6 mg sublingual nitroglycerin. Our results show that with modern digital subtraction techniques, not only stenosis geometry, but also coronary flow reserve can be determined at rest and during exercise conditions.

[Abnormal coronary vasomotility in subjects with normal coronary arteries and reduced reserve of coronary flow]. / Abnorme vasomotilità coronarica in soggetti con coronarie normali e ridotta riserva di flusso coronarico.

A reduced coronary flow reserve has been reported in patients with ischemia-like symptoms and normal coronary arteries. In 13 such subjects both coronary vasomotion and flow reserve were studied. The luminal area of the proximal and distal third of the left anterior descending and left circumflex artery were determined by biplane quantitative coronary arteriography using a computer-assisted system. Subjects were studied at rest, during submaximal supine bicycle exercise (4.0 min, 116 W) and 5 min after sublingual administration of 1.6 mg nitroglycerin. Heart rate, mean pulmonary and aortic pressure as well as the percent change of both proximal and distal luminal area were determined. In 10 of the 13 subjects, coronary sinus blood flow was measured by coronary sinus thermodilution technique at rest and after dipyridamole infusion (0.5 mg/Kg in 15 min) 10 +/- 5 days after quantitative coronary arteriography. Coronary flow ratio (dipyridamole/rest) and coronary resistance ratio (rest/dipyridamole) were determined in these subjects. Subjects were divided into 2 groups according to the behaviour of the coronary vessels during exercise (vasodilation = Group 1, vasoconstriction = Group 2). Coronary vasodilation of the proximal (luminal area + 26%; p less than 0.001) and distal (+ 45%; p less than 0.001) artery was observed in 7 subjects (Group 1) during exercise and after sublingual nitroglycerin (+46%; p less than 0.001 and +99%; p less than 0.001, respectively). In Group 2 (n = 6), however, there was coronary vasoconstriction of the distal vessel segments (-24%; p less than 0.001) during exercise, whereas the proximal coronary artery showed vasodilation (+ 26%; p less than 0.001) during exercise. Following sublingual nitroglycerin, both vessel segments elicited vasodilation (distal coronary + 44%; p less than 0.001, proximal coronary artery +47%; p less than 0.001). Coronary flow ratio amounted to 2.5 in Group 1 and to 1.2 in Group 2 (p less than 0.05) and coronary resistance ratio to 2.7 in Group 1 and to 1.2 in Group 2 (p less than 0.05), respectively. Thus, among subjects with ischemia-like symptoms and normal coronary arteries there is a subgroup of patients (Group 2) with an abnormal dilator response of the distal coronary arteries to the physiologic dilator stimulus of exercise and a reduced dilator capacity of the resistance vessels after dipyridamole (= abnormal coronary vasodilator syndrome). The nature of this exercise-induced distal coronary vasoconstriction is not clear but might be due to an abnormal neurohumoral tone which may cause or contribute to the blunted vascular response during exercise.

Right ventricular dysplasia: angiographic study.

At the moment, the most reliable method for diagnosing right ventricular dysplasia is considered to be angiography. Morphological alterations such as the presence of akinetic/dyskinetic areas, aneurysmatic dilatations and deep anteroapical fissuring, not necessarily associated with an increase in ventricular volume, are understood to be angiographic criteria indicating dysplasia. To verify their diagnostic value, these abnormalities have been evaluated in: (1) 33 patients suspected of having dysplasia because of PVBs with LBBB morphology and with 'borderline' involvement of the right ventricle or without instrumental evidence of cardiac disease (Group A); (2) 16 subjects with no arrhythmia and normal left ventricular angiography, coronary and bioptic findings (Group B); (3) 36 patients with a clinical, angiographic and bioptic diagnosis of dilated idiopathic cardiomyopathy (Group C). In 48.5% of the patients in Group A, angiography showed localized akinesia/dyskinesia (12 patients), small conical outpouchings persisting during systole (10 patients) and apical deep fissuring (two patients). In 81% of these patients, endomyocardial biopsy showed the presence of fibrous and/or adipose tissue in at least 20% of the examined sample. Angiographic abnormalities suggesting dysplasia were found in none of the normal subjects and only in two of the 36 patients with dilated cardiomyopathy (5.5%).

[Effect of intracoronary and intravenous administration of propranolol on coronary vasomotility at rest and during exercise]. / Effetto della somministrazione endocoronarica ed endovenosa di propranololo sulla vasomotilità coronarica a riposo e durante esercizio.

The effect of intracoronary and intravenous propranolol on coronary vasomotion was evaluated in 30 patients with coronary artery disease. Luminal area of a normal and a stenotic coronary segment was determined at rest, during supine bicycle exercise and 5 min after 1.6 mg sublingual nitroglycerin administered at the end of the exercise test using biplane quantitative coronary arteriography. Patients were divided into 3 groups: Group I (n = 12) served as control Group II consisted of 10 patients with intracoronary administration of 1 mg propranolol and Group III of 8 patients with intravenous administration of 0.1 mg/kg propranolol prior to the exercise test. In the control Group there was coronary vasodilation (+23%, p less than 0.01) of the normal and coronary vasoconstriction (-29%, p less than 0.001) of the stenotic vessel segment during bicycle exercise. After sublingual administration of 1.6 mg nitroglycerin there was vasodilation of both normal (+40%, p less than 0.001 vs rest) and stenotic (+12%, NS vs rest) segments. In Group II intracoronary propranolol was not accompanied by a change in coronary area but both normal (+13%, p less than 0.05) and stenotic (+22%, p less than 0.05) segments showed coronary vasodilation during bicycle exercise. After sublingual nitroglycerin there was further vasodilation of both normal (+31%, p less than 0.001 vs rest) and stenotic (+45%, p less than 0.01 vs rest) arteries. In Group III intravenous administration of propranolol was associated with a decrease in coronary luminal area of both normal (-24%, p less than 0.001) and stenotic (-41%, p less than 0.001) segments. During dynamic exercise there was coronary vasodilation of both segments when compared to the data after intravenous injection of propranolol but there was no change in luminal area (normal vessel-2%, NS vs rest; stenotic vessel-3%, NS vs rest) when compared to the resting data. After sublingual administration of 1.6 mg nitroglycerin both normal (+21%, p less than 0.001) and stenotic (+46%, p less than 0.001) segments showed coronary vasodilation. It is concluded that supine bicycle exercise in patients with coronary artery disease is associated with vasodilation of the normal and vasoconstriction of the stenotic coronary arteries. Intravenous administration of propranolol is followed by coronary vasoconstriction of both normal and stenotic coronary arteries probably due to secondary mechanisms (reduction in heart rate and contractility) because it is not observed after intracoronary injection of propranolol and it is overridden by bicycle exercise and sublingual nitroglycerin.