Biomedical subjects

L Chiariello

Publications and source records attributed to L Chiariello.

At least 37 records · Page 2Linked to original sources

PubMed2000

Regional distribution and timing of wall motion abnormalities during echo-dipyridamole stress test in patients with stable angina: the elusive link between coronary stenoses and myocardial ischemia.

BACKGROUND: Classic experimental studies have shown that in the presence of a flow-limiting coronary artery stenosis, myocardial ischemia during metabolic or pharmacological arteriolar vasodilation causes wall motion abnormalities, which precede electrocardiographic (ECG) changes in the myocardial regions supplied by the stenotic branch. The aim of this study was to establish whether in patients with chronic stable angina the regional distribution of wall motion changes and sequence of ischemic events are similar to that observed in experimental models, as currently believed. METHODS: The study population consisted of 20 men and 4 women (mean age 59 +/- 10 years) who were recruited on the basis of the following criteria: 1) a history of chronic stable angina without clinical and instrumental evidence of previous myocardial infarction; 2) reproducible positive exercise tests for ECG myocardial ischemia and anginal pain; 3) angiographically normal left ventricular function; 4) isolated stenosis of the left anterior descending coronary artery (LAD). Patients underwent continuous 12-lead ECG and echocardiographic monitoring during dipyridamole infusion. RESULTS: During dipyridamole infusion 3 patients (13%) did not develop echocardiographic changes, ECG changes or angina, 14 (58%) exhibited ECG changes, 18 (75%) lamented angina and 16 (67%) developed echocardiographic changes. In 5 of these 16 patients (31.5%) echocardiographic changes occurred in LAD-dependent territories only, in 5 they occurred in non-LAD-dependent territories only (31.5%) and in 6 (37%) they occurred in both LAD- and non-LAD-dependent territories. A total of 14 patients exhibited both echocardiographic and ECG changes and/or angina. In 6 of these 14 patients (43%) echocardiographic changes were the first ischemic events; in the remaining 8 patients (57%) ECG changes and/or angina were the first ischemic events. CONCLUSION: In the majority of patients during dipyridamole infusion regional wall motion changes occur in territories supplied by non-stenotic coronary artery branches; they are probably caused, therefore, by distal vessel dysfunction. Furthermore, the sequence of ischemic events is different in individual patients. These findings indicate that in stable angina the mechanisms of ischemia are multiple and that the link between coronary stenoses and myocardial ischemia is very elusive.

Adult↗

PubMed2000

[Atrial septal aneurysm with cerebral ischemia: potential pathogenetic role of associated cerebral vascular malformation].

Atrial septal aneurysm can be associated with other cardiovascular diseases such as atrial septal defect, patent ductus arteriosus, pulmonary hypertension and cerebrovascular events (transient ischemic attack or stroke). The introduction of transthoracic and more recently transesophageal echocardiography allowed for a more frequent observation of this pathology and also suggested that atrial septal aneurysm is a risk factor for cerebral ischemia. However, the pathophysiological pathway is still unclear. In January 1997 a 33-year-old man was admitted to our hospital because of atrial septal aneurysm and a previous cerebrovascular event. Magnetic resonance imaging revealed a cerebrovascular malformation and transesophageal echocardiography confirmed the presence of atrial septal aneurysm. We hypothesize that a common etiopathogenetic pathway may cause both the cardiac and cerebrovascular anomaly and that the latter may be responsible alone for cerebral ischemic events; thus in the presence of an atrial septal aneurysm associated with a cerebrovascular malformation, a conservative medical approach may be the treatment of choice.

Adult↗

PubMed2000

Ischemic preconditioning during coronary angioplasty is preserved in elderly patients.

BACKGROUND: To establish whether the adaptation to ischemia observed in humans during percutaneous transluminal coronary angioplasty (PTCA) after repeated balloon inflations, i.e. a clinical correlate of ischemic preconditioning, is preserved in elderly patients. METHODS: We studied 53 consecutive patients undergoing successful angioplasty for an isolated stenosis of a major epicardial coronary artery. On the basis of age, patients were separated into terciles: patients in the lower and middle terciles were grouped together (Group 1, adult patients, n = 24, mean age 50 +/- 6 years) and compared with those in the upper tercile (Group 2, elderly patients, n = 29, mean age 68 +/- 3 years). Intracoronary electrocardiogram was obtained at the end of the first two balloon inflations. Collateral recruitment during repeated balloon inflations was assessed by using an intracoronary Doppler guide wire (23 patients) or by using an intracoronary pressure guide wire (30 patients). RESULTS: In Group 1, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 3 vs 13 +/- 5 mm, p < 0.001). Similarly, in Group 2, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 4 vs 13 +/- 6 mm, p < 0.001). In both groups, collateral recruitment did not change from the first inflation to the second inflation (p = 0.1). CONCLUSIONS: Our study confirms that adaptation to ischemia during repeated balloon inflations in the setting of PTCA is independent of collateral recruitment and, therefore, is mainly due to ischemic preconditioning. More importantly, our study indicates that ischemic preconditioning is preserved in elderly patients.

Aged↗

PubMed2000

Anterior diaphragmatic hernia misinterpreted by X-ray, echocardiography, computed tomography scanning and magnetic resonance imaging.

We report the case of a 23-year-old man who was admitted to our Division with the diagnosis of pericardial lipoma. Chest X-ray, echocardiography and magnetic resonance imaging failed to reveal an anterior diaphragmatic hernia containing a small part of the stomach with a big prehernial lipoma that were found at surgery. We believe that in all cases of suspected pericardial lipoma a diaphragmatic hernia should be expected.

Adult↗

PubMed2000

Mechanisms of myocardial ischemia in a patient with left main coronary artery atresia.

This report describes the different clinical and instrumental manifestations of coronary ischemia in a patient with left main coronary artery atresia. Exercise test and thallium-201 perfusion scintigraphy during isometric exercise test were negative for angina and electrocardiographic changes. Conversely, dipyridamole infusion caused severe angina, marked ST-segment changes and diffuse thallium-201 uptake abnormalities. This peculiar anatomical condition offers the opportunity of high-lighting the role played by the microcirculation in determining myocardial ischemia.

Adult↗

PubMed2000

[Bentall-DeBono intervention: 8 years of clinical experience].

BACKGROUND: Annulo-aortic ectasia is a dilation of the aortic root with the involvement of the Valsalva sinuses. In 1968 Bentall and DeBono proposed to replace the aortic valve, the Valsalva sinuses and the ascending aorta with a composite tube graft containing aortic valve prosthesis. Consequently coronary ostia had to be reimplanted on the prosthetic tube. Recently the use of new materials has resulted in a more acceptable operative risk, and postoperative bleeding and late mortality have been reduced. METHODS: From January 1991 to December 1998, 44 out of 241 patients were operated on with the Bentall-DeBono procedure, affected by dissecting or expansive aneurysm of the ascending aorta. Of the 44 patients (35 males, 9 females, mean age 53.7 years), 3 presented with acute aortic dissection, 5 were asymptomatic, 10 were in NYHA functional class II, 14 in class III, 9 in class IV, and 2 in CCS class 4; 1 patient had dysphonia; 37 patients presented with isolated aortic regurgitation, and 7 associated aortic valvular stenosis. The diagnosis of acute dissection was made by transesophageal echocardiography and that of expansive aneurysm by thorax helical computed tomographic scanning and/or magnetic resonance imaging and cardiac catheterization. Follow-up was obtained in 100% of the patients for an average of 23 +/- 20.9 months (range 4-79 months). RESULTS: Four patients (9%) died; in 4 patients (9%) postoperative bleeding needed reoperation, in 5 (11.4%) a permanent pacemaker for atrioventricular block was implanted, and 1 patient (2.3%) had transient hemiparesis. At univariate analysis predictive factors for operative risk were NYHA functional class IV (p < 0.005) and atherosclerotic etiology (p < 0.05). At follow-up 7 late deaths occurred for an actuarial survival at 24 months of 75 +/- 9%. Causes were sudden death in 3 patients, cardiac failure in 3 and stroke in 1 patient; 31 surviving patients (94%) were in NYHA functional class I and 2 patients in class II (6%). CONCLUSIONS: The Bentall-DeBono procedure involves moderate risk with good results; clinical presentation and associated valvular pathology influence early and mid-term results.

Adult↗

PubMed1999

Ischemic preconditioning in humans: models, mediators, and clinical relevance.

Ischemic preconditioning, a powerful form of endogenous protection against myocardial infarction, has been demonstrated in several animal species and, recently, in isolated human cardiomyocytes. For both logistic and ethical reasons, no clinical study can meet the strict conditions of experimental studies on preconditioning with infarct size as the end-point. Nevertheless, the demonstration of adaptation to ischemia observed during in vitro studies on human atrial trabeculae, in patients in the setting of coronary bypass surgery, and in the setting of coronary angioplasty in the absence of collateral vessel recruitment strongly suggests that ischemic preconditioning occurs in humans. This notion is further supported by the observation that in these human models, the adaptation to ischemia is influenced by drugs acting on K(ATP) channels and on purinergic and alpha-adrenergic receptors, similar to what is observed in accepted experimental models of ischemic preconditioning. This important form of myocardial endogenous protection may also play a role in the warm-up phenomenon and in mediating the beneficial effects of preinfarction angina. The demonstration of ischemic preconditioning in humans and the identification of some of its mediators suggests that in patients at high risk for myocardial infarction, drugs known to block this endogenous form of protection should be used with caution, whereas drugs known to elicit preconditioning might have a relevant therapeutic role.

Angina Pectoris↗

PubMed1999

Coronary artery stent placement in patients with variant angina refractory to medical treatment.

We performed a prospective study to establish the efficacy of coronary stent placement in a highly selected group of patients with focal coronary artery spasm in whom anginal attacks could not be prevented by full medical therapy. The results of this study indicate that intracoronary stent placement may represent an alternative and feasible treatment for patients with vasospastic angina refractory to aggressive medical therapy.

Angina Pectoris, Variant↗

PubMed1999

Exercise-induced myocardial ischemia triggers the early phase of preconditioning but not the late phase.

The aim of the present study was to establish whether exercise-induced ischemia triggers the second window of protection in 15 patients with coronary artery disease undergoing 2 consecutive treadmill exercise tests and a third test 24 hours later. Our findings confirm that a first exercise-induced ischemic challenge induces the early phase of preconditioning but not the late phase, thus suggesting that either a late protective effect of preconditioning does not exist in the setting of demand ischemia or, if it exists, it must be weaker than the early protective effect.

Aged↗

PubMed1999

Cardiac echinococcosis causing coronary artery disease.

We report a case of cardiac echinococcosis in a patient who had sustained an acute myocardial infarction 1 month previously. The coronary angiographic study revealed an isolated complete intrinsic obstruction of the left anterior descending coronary artery in the area of the cyst. The cyst was surgically removed. Coronary artery bypass grafting was not performed because of distal myocardial scarring. Coronary arteriography should routinely be performed in all patients with cardiac echinococcosis.

Aged↗

PubMed1999

Recovery of LV contractility in man is enhanced by preischemic administration of enflurane.

BACKGROUND: Volatile anesthetics enhance postischemic functional recovery in animal models; this effect has not been investigated in man. METHODS: Twenty-two patients undergoing coronary surgery were randomized to enflurane administration (0.5% to 2%) for 5 minutes to reduce systolic blood pressure by 20% to 25% immediately before cardioplegic arrest. Left ventricular contractility was assessed by pressure-area relations using echocardiographic automated border detection during inflow occlusion before and after cardiopulmonary bypass. Linear regression analysis in 16 patients with paired data sets assessed changes in contractility. RESULTS: The relation was highly linear (r = 0.95+/-0.02). A change of slope versus the change in x intercept was detected in controls (mean difference, 16.1 mm Hg/cm2, 95% confidence limits, 5.9 to 26.3; 2.2 cm2, 95% confidence limits, -1.1 to 5.5; p = 0.007), which was different from those of treated patients (mean difference, 0.7 mm Hg/cm2, 95% confidence limits, -2.2 to 3.7; -0.06 cm2, 95% confidence limits, -1.6 to 1.5; p > 0.2). Analysis of covariance in the overall group confirmed a significant effect of treatment (p = 0.002). CONCLUSIONS: Enflurane enhances postischemic functional recovery, possibly through pharmacologic preconditioning of myocardium.

Aged↗

PubMed1999

Unusual origin and fistulization of an aortic pseudoaneurysm: "off-pump" surgical repair.

Aortic pseudoaneurysm is an unusual complication of cardiac operations. The origin depends on the site of arterial wall disruption. Rupture into the right side of the bronchial tree is an exceedingly rare evolution. Repair is commonly performed using cardiopulmonary bypass. In our report a male patient underwent two procedures for aortic dissection, and 6 months after the second operation massive hemoptysis appeared abruptly. A false aneurysm rose from a graft-to-graft anastomotic site and ruptured into a segmental bronchus of the right upper lobe. Repair was performed without cardiopulmonary bypass.

Anastomosis, Surgical↗

PubMed1999

A review of aortopulmonary fistulas in aortic dissection.

Aortopulmonary fistula is an exceedingly rare complication of aortic dissection. Only 4 cases in acute dissection and 8 cases in the chronic one have been published previously. We report the thirteenth case and a review of the literature. A man underwent an operation for type A aortic dissection. At surgery, a fistula was discovered between the false lumen and the main pulmonary artery, although the preoperative investigations did not suggest such a complication.

Aortic Dissection↗

PubMed1999

Coronary flow reserve early and late after minimally invasive coronary artery bypass grafting in patients with totally occluded left anterior descending coronary artery.

BACKGROUND: The impairment of flow reserve of the left anterior descending coronary artery in the early postoperative period in patients receiving a left internal thoracic artery graft has been related to the effects of cardiopulmonary bypass. Indeed, the late improvement in flow has been attributed to a late increase in left internal thoracic artery diameter. METHODS: We evaluated 12 patients who underwent minimally invasive direct coronary artery bypass surgery with the internal thoracic artery used to graft an occluded left anterior descending artery without extracorporeal circulation. Early and 6 months after the operation, patients underwent a second angiogram of the left internal thoracic artery graft and assessment of coronary flow reserve by use of an intracoronary 0.014-inch Doppler guide wire. RESULTS: At the late study, coronary flow reserve had increased compared with the early postoperative data from 1.8 +/- 0.4 (standard deviation) to 2.5 +/- 0.6 (P =.002) because of a significant decrease in baseline averaged peak velocity (32.4 +/- 6.2 vs 21.3 +/- 6.4 cm/s, P =.002), whereas the hyperemic values were similar (51 +/- 6 vs 53.7 +/- 21.9 cm/s, P =.6). The diameters of the thoracic artery (2.1 +/- 0.3 vs 2.2 +/- 0.3 mm, P =. 7) and the left anterior descending coronary artery (1.8 +/- 0.1 vs 1.8 +/- 0.2 mm, P =.5), as well as myocardial oxygen consumption (106 +/- 14 vs 101 +/- 16 mm Hg. beats/min. 10(-2), P =.5), were unchanged. CONCLUSIONS: Our findings suggest that the late improvement in coronary flow reserve is independent of the diameter of the graft and probably reflects an early distal coronary vessel dysfunction, which normalizes with time.

Analysis of Variance↗

PubMed1999

Effects of naloxone on myocardial ischemic preconditioning in humans.

OBJECTIVES: We attempted to establish whether naloxone, an opioid receptor antagonist, abolishes the adaptation to ischemia observed in humans during coronary angioplasty after repeated balloon inflations. BACKGROUND: Experimental studies indicate that myocardial opioid receptors are involved in ischemic preconditioning. METHODS: Twenty patients undergoing angioplasty for an isolated stenosis of a major epicardial coronary artery were randomized to receive intravenous infusion of naloxone or placebo during the procedure. Intracoronary electrocardiogram and cardiac pain (using a 100-mm visual analog scale) were determined at the end of the first two balloon inflations. Average peak velocity in the contralateral coronary artery during balloon occlusion, an index of collateral recruitment, was also assessed by using a Doppler guide wire in the six patients of each group with a stenosis on the left anterior descending coronary artery. RESULTS: In naloxone-treated patients, ST-segment changes and cardiac pain severity during the second inflation were similar to those observed during the first inflation (12+/-6 vs. 11+/-7 mm, p = 0.3, and 58+/-13 vs. 56+/-12 mm, p = 0.3, respectively), whereas in placebo-treated patients, they were significantly less (6+/-3 vs. 13+/-6 mm, p = 0.002 and 31+/-21 vs. 55+/-22 mm, p = 0.008, respectively). In both naloxone- and placebo-treated patients, average peak velocity significantly increased from baseline to the end of the first inflation (p = 0.04 and p = 0.02, respectively), but it did not show any further increase during the second inflation. CONCLUSIONS: The adaptation to ischemia observed in humans after two sequential coronary balloon inflations is abolished by naloxone and is independent of collateral recruitment. Thus, it is due to ischemic preconditioning and is, at least partially, mediated by opioid receptors, suggesting their presence in the human heart.

Aged↗

PubMed1999

Effect of acetylsalicylate on cardiac and muscular pain induced by intracoronary and intra-arterial infusion of bradykinin in humans.

OBJECTIVES: This study assessed the algesic activity of bradykinin (BK) in humans and the effects of acetylsalicylate on muscular and cardiac BK-induced pain. BACKGROUND: Bradykinin is released by the ischemic myocardium and may be involved in the genesis of ischemic pain. METHODS: Increasing doses of BK (from 30 to 960 ng/min) were randomly infused, for periods of 2 min each, into the iliac artery of 10 patients. The same protocol was repeated 30 min after the IV administration of 1 g of acetylsalicylate. In eight other patients with coronary artery disease, the same increasing doses of BK, for periods of 2 min each, were infused into the left coronary artery. The same protocol was repeated 30 min after the IV administration of 1 g of acetylsalicylate. Time to pain onset and maximal pain severity were obtained. RESULTS: Before acetylsalicylate administration, all patients experienced pain during intra-iliac infusion of BK. After acetylsalicylate, eight patients did not experience any pain during BK infusion (p = 0.0014), and in the two remaining patients, time to pain onset and maximal pain severity were similar to those recorded before acetylsalicylate. Before acetylsalicylate administration, all patients experienced pain similar to their habitual angina during intracoronary BK infusion. After acetylsalicylate, six patients did not experience any pain during BK infusion (p = 0.0098), whereas in the two remaining patients time to pain onset and maximal pain severity were similar to those recorded before acetylsalicylate. CONCLUSIONS: Intra-iliac infusion of BK causes muscular pain, and its intracoronary infusion in patients with coronary artery disease causes cardiac pain, which is similar to their habitual angina. The BK-induced pain is abolished or reduced by acetylsalicylate, thus suggesting that acetylsalicylate-sensitive mediators, such as prostaglandins, are involved in its pathogenesis.

Aged↗

PubMed1999

Effects of K(ATP) channel blockade by glibenclamide on the warm-up phenomenon.

AIMS: The increased tolerance to myocardial ischaemia observed during the second of two sequential exercise tests, i.e. the warm-up phenomenon, has been proposed as a clinical model of ischaemic preconditioning. As ATP-sensitive K+ channels appear to be a mediator of ischaemic preconditioning in both experimental and clinical studies, the aim of this study was to investigate the role of K(ATP) channels in the warm-up phenomenon. METHODS AND RESULTS: Twenty-six patients with coronary artery disease were randomized to receive 10 mg oral glibenclamide, a selective ATP-sensitive K+ channel blocker, or placebo. Sixty minutes after glibenclamide or placebo administration, patients were given an infusion of 10% dextrose (8 ml x min(-1)) to correct glucose plasma levels or, respectively, an infusion of saline at the same infusion rate. Thirty minutes after the beginning of the infusions, both patient groups underwent two consecutive treadmill exercise tests, with a recovery period of 15 min to re-establish baseline conditions. Before exercise tests, blood glucose levels were similar in placebo and glibenclamide groups (96 +/- 10 vs 105 +/- 22 mg x 100 ml(-1), P=ns). After placebo administration, rate-pressure product at 1.5 mm ST-segment depression significantly increased during the second exercise test compared to the first (220 +/- 41 vs 186 +/- 29 beats x min(-1) x mmHg x 10(2), P<0.01), but it did not change after glibenclamide (191 +/- 34 vs 187 +/- 42 beats x min(-1) x mmHg x 10(2), P=ns), with a significant drug-test interaction (P=0.0091, at two-way ANOVA). CONCLUSIONS: Glibenclamide, at a dose previously shown to abolish ischaemic preconditioning during coronary angioplasty, prevents the increase of ischaemic threshold observed during the second of two sequential exercise tests. These findings confirm that ischaemic preconditioning plays a key role in the warm-up phenomenon and that in this setting is, at least partially, mediated by activation of ATP-sensitive K+ channels.

Adenosine Triphosphate↗

PubMed1999

[Percutaneous transvenous biopsy for the diagnosis of a right atrial myxoma].

Intracardiac tumors are generally diagnosed by transthoracic echocardiography, transesophageal echocardiography and, more recently, magnetic resonance imaging. However, these techniques do not permit a histopathologic diagnosis. When surgery is not indicated because of limited hemodynamic changes but the benign nature of the tumoral mass is questionable, percutaneous transvenous biopsy, when technically feasible, may represent an alternative approach. In this case report, we utilized percutaneous transvenous biopsy to obtain specimens from a right atrial mass in a 39-year-old woman.

Adult↗