Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of halothane on net myocardial oxygen balance of ischemic myocardium was studied in the non-failing canine heart. Myocardial ischemia was produced by repeated reversible occlusions of a coronary artery; the severity of ischemia was estimated by summating ST-segment elevations (sigma ST) obtained by epicardial ECG mapping at 15 to 18 sites. Control measurements were obtained before and after administration of halothane (0.75 per cent) to six dogs with chloralose-urethane basal anesthesia. Halothane was associated with significant decreases of systemic arterial pressure (P less than .001), heart rate (P less than .01), and the product of systolic arterial pressure X heart rate (P less than .01), an indirect index of myocardial oxygen consumption, while left atrial pressure remained unchanged at normal levels. sigmaST during occlusion was less (P less .001) during halothane (26.5 +/- 7.4 (SD) mv) than before (36.6 +/- 5.4 mv) or after (34.4 +/- 8.2 mv) its administration. Thus, halothane decreased the severity of experimentally-induced myocardial ischemia in the non-failing canine heart. The data suggest that, in the absence of ventricular failure, halothane influences the relationship between myocardial oxygen supply and demand in a favorable direction when coronary blood flow is limited.
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PMID:Halothane-induced decrease in experimental myocardial ischemia in the non-failing canine heart. 96 78

Severe myocardial ischemia, when sustained, leads to a predictable sequence of events, including myocardial necrosis, expansion of the infarct, and later its replacement by scar tissue. The nonischemic tissue sustains ventricular function, but it frequently adapts to the extra load placed on it by dilating. The enlargement and remodeling of the left ventricle may lead to ventricular failure and arrhythmias. Rational management to prevent these complications includes restoration of the patency of the occluded vessel and ventricular unloading. These two interventions may be useful both early and late in the course of infarction.
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PMID:Ventricular enlargement and remodeling following acute myocardial infarction: mechanisms and management. 183 91

Regional wall motion abnormalities (RWMA) detected by intraoperative transesophageal echocardiography (TEE) are thought to be sensitive markers of myocardial ischemia. To assess the prognostic significance of RWMA as compared with other less costly technologies such as electrocardiography (ECG) and hemodynamic measurements [blood pressure (BP) and pulmonary artery (PA) pressure], 50 patients were prospectively studied who were undergoing elective coronary artery bypass graft (CABG) surgery using continuous TEE, ECG (Holter), and hemodynamic measurements during the prebypass, postbypass, and early postoperative intensive care unit (ICU) periods (first 4 h). Echocardiographic and ECG evidence of ischemia was characterized during each of these three periods and related to adverse clinical outcomes (postoperative myocardial infarction, ventricular failure, and cardiac death). Clinicians were blinded to the TEE and ECG information. The prevalence of myocardial ischemia during the perioperative periods was as follows: prebypass, 20% (TEE) versus 7% (ECG); postbypass, 36% (TEE) versus 25% (ECG); ICU 25% (TEE) versus 16% (ECG). Neither prebypass TEE ischemia nor ECG ischemia occurring in any of the three periods predicted adverse outcome. In contrast, postbypass TEE ischemia was predictive of outcome: six of 18 patients with postbypass TEE ischemia had adverse outcomes versus 0 of 32 without TEE ischemia (P = 0.001). Seventy-three percent of the echocardiographic ischemic episodes occurred without acute change (+/- 20% of control) in heart rate, BP, or PA pressure. The authors conclude that: 1) prebypass myocardial ischemia was relatively uncommon, 2) the incidence of ECG and TEE ischemia was highest in the postbypass period, and 3) postbypass RWMA were related to adverse clinical outcome.
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PMID:Prognostic importance of postbypass regional wall-motion abnormalities in patients undergoing coronary artery bypass graft surgery. SPI Research Group. 278 9

From December 1975 to September 1989, nine children, ages 0.6-15.8 years (mean = 8.1 years) and weighing 5-44 kg (mean = 24 kg), were identified as requiring intraaortic balloon pump support. Indications included ventricular failure refractory to maximal conventional therapy, inability to wean from cardiopulmonary bypass, and myocardial ischemia. Prior to insertion of the balloon catheter, mean systolic blood pressure was 64 mmHg, one to four cardiotonic medications were being administered, mechanical ventilation was being performed in eight patients, and mean urine output was 0.4 ml/kg/min in eight. Following balloon catheter insertion, mean urine output increased to 0.9 ml/kg/min. Four patients survived following discontinuation of the balloon catheter 12-96 h (mean = 59 h) after initiation. Though complications such as loss of distal lower extremity pulses, sepsis, thrombocytopenia, and abdominal distention were observed, most could be attributed to other causes. Thus, the intraaortic balloon pump is a valuable addition to conventional medical therapy in the treatment of refractory cardiogenic shock in children.
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PMID:Intraaortic balloon pump management of refractory congestive heart failure in children. 845 16

Prolonged closed chest cardiopulmonary bypass for severe total biventricular myocardial dysfunction requires invasive decompression of the left heart. The authors have developed an elongated helical coil that is permanently attached to the distal 8-10 cm of a flow directed Swan-Ganz catheter. When properly positioned, the helical coil kept the pulmonary artery (PA) and the tricuspid valves open, and allowed closed chest retrograde decompression of the left heart. The authors have evaluated the merits of closed chest cardiopulmonary bypass with decompression of the left heart in this manner in four sheep subjected to 30 min of warm global myocardial ischemia, along with induced ventricular fibrillation. All sheep developed severe global myocardial failure, with no left ventricular (LV) ejection. The authors have shown that pulmonary blood flow during cardiopulmonary bypass was reversed from the left heart, across the lungs, and into the right heart. The wedge pressure never exceeded 12 mmHg at any time, attesting to good decompression during periods of total ventricular failure, during partial recovery with some LV ejection, and after good recovery of LV function, followed by weaning from bypass after 44, 67, and 78 h of such support. One sheep could not be weaned from bypass, even after 5 days of CPBP. Lung function in all sheep remained unimpaired throughout, and there was no wound bleeding. The authors conclude that in this model of total myocardial failure, and while on closed chest CPBP, at all times and with all degrees of myocardial dysfunction, excellent LV decompression with the helical coil catheter was attained.
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PMID:Cardiopulmonary bypass through peripheral cannulation with percutaneous decompression of the left heart in a model of severe myocardial failure. 938 45

From November, 1968, through December, 1976, intraaortic balloon pump (IABP) circulatory support was used 747 times in 728 patients. Overall in-hospital survival was 413/747 (56.9%). Survival with IABP since 1974 has been 65% (286/440) compared to 24% (18/75) in 1968-1971 (P < 0.001). Two practical changes have been associated with this improvement: 1) broadened indications for, and earlier insertion of, IABP; and 2) more aggressive surgical treatment of the primary cardiac lesion. Cardiogenic shock or chronic ischemic ventricular failure accounted for 78.7% (59/75) of IABP in 1968-1971; during 1974-1976 only 26.4% (116/440) of IABP-supported patients were in these categories (P < 0.001). Since 1974, 58.2% (153/263) of IABP patients had an operative procedure following IABP insertion compared to 37.7% (23/611 prior to 1971 (P < 0.01). The major complication rate has remained unchanged at 8.5%. IABP-related mortality rate was 0.8% (6/728). Earlier, more liberal, use of IABP hemodynamic support has led to increased survival in a large number of patients with complications of acute myocardial ischemia. The low mortality associated with its use vindicates earlier institution of IABP support in cardiogenic shock.
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PMID:Clinical experience with intraaortic balloon pump support in 728 patients. 1474 Jun 92

The arrival of a patient with chest pain syndrome (precordial) to the emergency represents a diagnostic challenge for the physician. Around 6 million persons are seen each year at the Emergency units in the USA. More than half of the patients are admitted for their cardiac evaluation. Its cardiac origin is confirmed in 10 to 15%, and about 15% of them develop myocardial infarction. However, 5 to 10% of patients are dismissed and develop myocardial infarction during the next 48 h. The diagnosis of the infarct is inadvertent and/or patients is not hospitalized in 2 to 8%. The mortality rate is duplicated in none hospitalized patients. Frequently, a conservative observation conduct and/or diagnostic expectation is taken, with the consequent saturation of the intensive care unit that looses its critical character and avoids quick mobilization of the patient with an increase in costs. The clinical judgment, a meticulous clinical history, and careful physical examination play a key role in the differential diagnosis of the precordial pain syndrome; however, pain can be atypical, absent or manifest as an equivalent of pain, which does not exclude the diagnosis of myocardial infarction or ischemia. Likewise, chest pain in the presence of a normal conventional ECG at rest, non-diagnostic or with minimal variations, does not rule out the possibility of a coronary obstruction and does not mean that the pain is not of coronary origin. Other characteristics of the ECG, such as T wave and ST segment alterations, bundle branch block (BBB), LV hypertrophy, interpretation discrepancies, can pose doubts or mistakes in the diagnosis. Although its diagnostic information is essential, other non-invasive laboratory tests are needed, such as the treadmill stress ECG, serial bioenzymatic markers, and myocardial perfusion scintigraphy (SPECT and Gated-SPECT) at rest or under physical or pharmacologic stress. The advantages and disadvantages of the stress ECG, the echocardiography, magnetic resonance and PET are mentioned. The advantages of the SPECT and Gated-SPECT in the diagnosis and prognosis are: 1) great diagnostic objectivity; 2) high sensitivity and specificity; 3) diagnosis does not depend on evolution time of the ischemia and/or infarction, since SPECT diagnoses the initial primary modifications of ischemia; 4) diagnosis is achieved within the established limit of time, in less than 4 to 6 hours. The designed protocols allow to obtain the diagnosis between 30 min and 1:30 h; 5) assesses the myocardium at risk; 6) stratifies the risk and prognosis; 7) defines the site and 8) the involved coronary artery(les); 9) provides the functional significance of the anatomic obstruction; 10) quantifies the ventricular function, i.e., ejection fraction, systolic and diastolic volumes, systolic thickening, ventricular failure signs; 11) provides three-dimensional visualization of the mobility of the left ventricular wall; 12) diagnoses simultaneously the associated presence of ischemia and/or infarction of the right ventricle; 13) its high negative predictive value allows to dismiss immediately and with a great safety margin those patients in whom SPECT revealed normal perfusion; 14) costs are reduced without adversely compromising the safety of the patients. We describe the algorithm used as guideline for the early diagnosis in the presence or absence of ischemic heart disease in the patient with precordial or chest pain syndrome with normal or non-diagnostic ECG at arrival to the emergency ward. It is necessary to modified the clinical educational patterns and to revaluate the advantages and limitations of the clinical history, physical exploration, as well as of the conventional ECG at rest and other diagnostic methods used specifically in relation to the chest pain syndrome with a normal or non diagnostic conventional ECG. SPECT and Gated-SPECT scintigraphy is considered as the best individual and isolated non-invasive test for the diagnostic solution of the precordial syndrome at the Emergency Unit.
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PMID:[Chest pain syndrome in normal or non-diagnostic conventional ECG at the emergency service. Assessment with myocardial perfusion (SPECT) and ventricular function (Gated-SPECT)]. 1521 44

Coronary artery fistulas (CAF) are uncommon entities often associated with myocardial ischemia and high output failure. Surgical options include ligation of the fistula, with/without simultaneous coronary artery bypass grafting (CABG). We report a case of left main coronary artery (LMCA) fistula to the coronary sinus (CS), which was associated with high-output bi-ventricular failure, and moderate mitral (MR) and tricuspid regurgitation (TR), related to the volume overload and annular dilatation. This was tackled elegantly by off-pump CABG to protect the territories supplied by the LMCA, followed by ligation of the fistula. This resulted in resolution of the MR and TR. Intraoperative transesophageal echocardiogram (TEE) greatly facilitated the surgical treatment, by identifying the origin and the draining points for the fistula, and aided in the quantification of MR and TR, which had regressed sufficiently at the end of the procedure and did not require surgical correction. This article outlines the importance of multi-disciplinary treatment approach for this complex condition.
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PMID:Treatment of high-output coronary artery fistula by off-pump coronary artery bypass grafting and ligation of fistula. 1934 22

Although pharmacological and interventional advances have reduced the morbidity and mortality of ischemic heart disease, there is an ongoing need for novel therapeutic strategies that prevent or reverse progressive ventricular remodeling following myocardial infarction, the process that forms the substrate for ventricular failure. The development of cell-based therapy as a strategy to repair or regenerate injured tissue offers extraordinary promise for a powerful anti-remodeling therapy. In this regard, the field of cell therapy has made major advancements in the past decade. Accumulating data from preclinical studies have provided novel insights into stem cell engraftment, differentiation, and interactions with host cellular elements, as well as the effectiveness of various methods of cell delivery and accuracy of diverse imaging modalities to assess therapeutic efficacy. These findings have in turn guided rationally designed translational clinical investigations. Collectively, there is a growing understanding of the parameters that underlie successful cell-based approaches for improving heart structure and function in ischemic and other cardiomyopathies.
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PMID:Cell-based therapy for prevention and reversal of myocardial remodeling. 2263 82

Cardiogenic Shock (CS) is a major challenge in current cardiology. Over the last decade, cardiogenic shock mortality has decreased somewhat, but it still remains high, particularly when associated with ischaemic heart disease. The challenges are numerous and include prevention, accurate diagnosis, prompt management and effective therapies to support a failing heart and prevent multi-organ failure. Despite improvements in the care of Acute Coronary Syndrome (ACS), it remains the most common cause of CS. In addition to existing medical therapy, mechanical circulatory support has been proposed for the management of ventricular failure. The intra-aortic balloon pump was amongst the first widely used percutaneous mechanical support devices, and more recently, systems providing a higher level of support have been developed. Although the evidence supporting their use is limited, they have the potential to significantly reduce CS-associated mortality. In this narrative review, we summarize the available evidence and discuss the future directions regarding percutaneous mechanical circulatory support in patients with left ventricular dysfunction and CS complicating ACS.
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PMID:Mechanical Support in Cardiogenic Shock Complicating Acute Coronary Syndrome: Ready for Prime Time? 2934 84


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