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)

Toxic manifestations of digitalis are one of the most prevalent adverse drug reactions encountered in clinical practice. The estimated incidence is about 20% in hospitalized patients in the USA. The authors describe a rare case of myocardial "catecholamine necrosis" (anteroseptal myocardial infarction) during accidental digitalis intoxication. A male patient, 75 years old, suffering from cirrhosis and ascites, take on by mistake a tablet of digoxin 0.25 mg. four times at day for eleven days. He hadn't heart disease in the past. At the eleventh day the patient showed a deep tiredness and so he was submitted to a clinical examination and electrocardiogram. The ECG demonstrated an anteroseptal myocardial infarction in the second-third electrical stage. The patient was hospitalized. The successive examination revealed: very high plasma digitalis concentrations; an increase of the serum levels of CPK and LDH; a significant increase of plasmatic and urinary catecholamine levels which return to normal values after fifteen days; apical akinesia at the echocardiographic examination; no signs of residual myocardial ischemia to the echo-dypiridamole stress test; normal coronary artery to the coronary arteriography and absence of coronary artery spasm to the ergonovine test. Furthermore the abdominal echography and the abdominal computerized tomography didn't reveal surrenal disease but showed an important liver disease. The patient was free from other cardiac events in the follow-up. Generally, during the digitalis intoxication we observe various rhythm and conduction disturbances. Instead in this case no serious arrhythmias were registered and the main expression of the drug toxicity was an anteroseptal myocardial infarction with undamaged coronary artery. Also the usual extracardiac symptoms and signs of the digitalis intoxication were absent in this case. All these observations can be explained with the pathological increase of the cathecholamine levels, indirectly induced by digitalis; with the direct toxic effect of the drug at the myocardic level; with the contemporary absence of ionic disturbances; with the concomitant liver disease. The direct toxic effect of the digitalis produced an increase in calcium ions availability for the electromechanical coupling and an increase of the intramyocardial pressure; the increase of the adrenergic activity determined contemporary an increase in the oxygen consumption of the myocardial cells, a rise of vascular tone and coronary artery tone and a reduction of the duration of the diastole. All these factors provoked a "primary and secondary" ischemia which evolved toward a real "cathecholamine necrosis" and produced a myocardial infarction. This hypothesis explains the myocardial infarction in absence of injury at the coronary arteriography and without coronary spasm at the ergonovine test; moreover it explains the transient increase in cathecholamine plasma levels observed in the acute phases an normalized after fifteen days. The "cathecholamine necrosis" is an anatomical definition, nevertheless in our opinion it gives account of the rare clinical situation observed.
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PMID:[An unusual case of "catecholamine necrosis" caused by accidental digitalis poisoning]. 855 67

There are no standard criteria for the diagnosis of myocardial ischemia in akinetic segments during dobutamine stress echocardiography (DSE). The aim of the study was to assess the relation between different responses of akinetic segments during DSE and ischemia assessed by thallium-201 single-photon emission computed tomography (SPECT). Dobutamine-atropine stress echocardiography with simultaneous stress-reinjection thallium-201 SPECT was performed in 67 patients with old myocardial infarction significant and coronary artery stenosis. Fourteen myocardial segments were matched for both DSE and SPECT. Ischemia on SPECT was defined as reversible thallium defects. In 257 akinetic segments, 4 patterns during DSE were identified: (1) biphasic response in 41 segments (16%), defined as improvement at low dose (5 to 10 microgram/kg/min) followed by worsening at high dose; (2) persistent akinesia in 155 segments (60%); (3) akinesia becoming dyskinesia in 39 segments (15%); and (4) sustained improvement in 22 segments (9%). Reversible thallium defects were detected in 21 segments (51%) in group 1, in 20 segments (13%) in group 2, none in group 3, and in 2 segments in group 4 (9%). The prevalence of reversible defects in biphasic segments was higher compared with other patterns (p <0.00001 vs groups 2 and 3, p <0.005 vs group 4). The ischemic perfusion defect score was significantly higher in group 1 than group 2. The positive predictive value of biphasic response for reversible thallium defects was similar to that of stress-induced dyssynergia in normal segments at rest (51% vs 58%). It is concluded that of the various responses of akinetic segments to dobutamine infusion, the biphasic response is associated with the highest prevalence and greatest severity of ischemic on thallium SPECT. Observation of contractile response at both low- and high-dose DSE is a valuable approach for the diagnosis of myocardial ischemia in akinetic segments.
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PMID:Relation between contractile response of akinetic segments during dobutamine stress echocardiography and myocardial ischemia assessed by simultaneous thallium-201 single-photon emission computed tomography. 864 45

A patient with an obstructive hypertrophic cardiomyopathy and normal epicardial coronary arteries developed myocardial ischemia accompanied by a transitory apical akinesia. This wall motion dysfunction persisted for hours after the relief of myocardial ischemia.
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PMID:Myocardial stunning in hypertrophic cardiomyopathy with normal coronary arteries. 889 7

In patients with a previous myocardial infarction, controversy exists regarding the significance of postexercise ST-segment elevation in the infarct-related leads. Although usually admitted to be a sign of left ventricular dysfunction or myocardial aneurysm, other studies however have related this finding to transient myocardial ischemia and to the presence of jeopardized but viable myocardium in the infarct area. The aim of the present study was to assess the significance of postexercise ST-segment elevation in Q-wave leads as a marker of transmural ischemia or left ventricular dysfunction in 36 consecutive patients, 16 with exercise-induced ST-segment elevation in infarct-related leads. Patients were evaluated by treadmill exercise testing, coronary angiography and ventriculography, thallium-201 tomographic scintigraphy and radionuclide ventriculography within 3 months of the first myocardial infarction. Sixteen patients (group I) had exercise-induced ST segment elevation and 20 (group II) postexercise inversion, no change or pseudonormalization of the T wave in infarct-related leads. The study showed no difference in infarct-related artery, vessel disease or luminal diameter stenosis in groups I and II. The overall agreement between ST shifts and myocardial perfusion in the infarct area was 30.56% with a kappa coefficient of -0.33 (p = NS). The overall agreement between ST shifts and wall motion abnormalities was 69.44% with a kappa coefficient of 0.39 (p < 0.01), stress-induced ST-segment elevation being associated with severe wall contractile disorders in 85% of the patients. In conclusion stress-induced ST-segment elevation in Q wave leads, although not a marker of wall motion abnormalities, is associated with akinesia or dyskinesia of the left ventricular wall.
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PMID:Role of myocardial ischemia and left ventricular wall motion abnormalities as contributory factors in the genesis of exercise-induced ST-segment elevation in Q-wave myocardial infarction. 1054 77

Myocardial contraction behaves heterogeneously, being greater in subendocardial than in subepicardial layers. Similarly, during acute myocardial ischemia or infarction, the subendocardium is the first myocardial layer to suffer. Conventional two-dimensional echocardiography cannot distinguish the transmural extension of myocardial ischemia or infarction, showing akinesia also when only the subendocardium is affected. Novel ultrasonographic techniques (like tissue characterization with integrated backscatter or Doppler tissue imaging) and nuclear magnetic resonance tagging can investigate myocardial contraction in different transmural layers and distinguish subendocardial from transmural ischemia or infarction. With the advent of thrombolysis and primary angioplasty in the acute phase of myocardial infarction a correct diagnosis of the extension of myocardial necrosis cannot ignore its transmural wavefront development. The salvage of the subepicardial layer does not give direct information on overall myocardial thickening but is one of the major determinants of overall left ventricular dysfunction and size. Although it is still necessary to investigate this phenomenon, new ultrasonographic techniques give us important information and more opportunities to appropriate diagnosis and future treatment of cardiac patients.
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PMID:Transmural heterogeneity of myocardial contraction and ischemia. Diagnosis and clinical implications. 1080 84

The concept of left ventricular aneurysm has been a subject of controversy and it's not yet completely settled. This has some implications on the patients selection for surgery and explains the various non-invasive methods so far developed for the clinical assessment of patients with ventricular aneurysms. Seventy-one patients with ischemic heart disease, 65 with recent myocardial infarction, were studied by equilibrium radionuclide angiography (ERNA) in order to define left ventricular wall motion abnormalities. One hundred ERNA were undertaken, through the usual erytrocites in vivo labelling technic, employing a GE 400 T Gama-Camera GP. Image acquisition was through 400 cardiac cycles, on LAO (30 and 60 degrees) and left lateral. PAGE protocol was employed. Fourier transform was used in the present work to obtain phase and amplitude images, which actually became the main criteria to define aneurysmatic areas. Global ejection fraction, regional wall motion and regional ejection fraction were other parameters investigated. Wall motion abnormalities have been identified in all the 65 patients having suffered a myocardial infarction. Extensive areas of akinesia or localized dyskinesia were present in 40 patients (16.5%), while remainder 25 had just localized hypoakinesia. Phase image enabled the selection of LV areas of contraction delay in 19 of the 40 patients with extensive wall motion abnormalities (Group I). In such Group I we could identify an LV area with contrasting colour, defining the aneurysmatic LV portion. In the order 21 patients with extensive akinesia, no significant changes of colour were present on ventricular phase image (Group II) meaning absence of aneurysm. No phase disturbances were seen in the remainder 25 patients with MI (Group III) and the 6 patients with CAD without MI had normal phase images (Group IV). The percentage of akinetic segments was 39.1 and 35.4 in Group I and II, respectively (p = .53) while it was significantly lower in Group III 17.9%; p < .0001). LV ejection fraction was statistically different in the four groups considered (I = 30.0% +/- 3.7; II = 39.9% +/- 2.9; III = 49.0% +/- 2.5; IV = 62.0% +/- 3.2). The degree of phase delay in aneurysmatic zones was quantified by the phase histogram. Average value of phase for the left ventricle was 129.7 +/- 8.4 degrees, and for the aneurysm it was 238.0 +/- 5.0 with an average phase delay of 104.8 +/- 4.1 degrees. The association of phase and amplitude images and the measurements of phase and amplitude values on the histograms allowed the distinction of akinetic aneurysm (phase delay and low amplitude) from the dyskinetic aneurysms (phase delay and high amplitude). Half of the isotopic diagnosis of aneurysms have been confirmed by classic contrast angiography, and a third of then have undergone surgery. The two dyskinetic aneurysms that have been submitted to aneurysmectomy had pos-operative improvement of LV function. On summary, phase and amplitude analysis by the Fourier method, which is independent of LV geometry, showed that LV regions with high phase values are associated with severe regional wall motion abnormalities and low ejections fractions. The definition of the sequence and amplitude of ventricular contraction allows the distinction of akinetic and dyskinetic aneurysms, anticipating the method as a valid contribution for the screening of patients likely to benefit from aneurysmectomy.
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PMID:[Study of post-myocardial infarction ventricular aneurysms with equilibrium radionuclide angiography. Significance of Fourier analysis]. 1151 5

The diagnosis of viable myocardium in patients with ischemic heart disease (IHD) with left ventricular (LV) dysfunction is essential for prediction of effectiveness and validity of myocardial revascularization as well as of prognosis in such patients. Great advances in intravascular reconstructive interventions on coronary arteries makes this diagnosis still more important. For diagnosis of reversible forms of LV myocardial dysfunction (stunned and hibernating myocardium) such highly informative methods as positron-emission tomography, single-photon emission computed tomography, nuclear magnetic resonance may be applied but they are not easily available because of high cost. Introduction of stress echo-CG into cardiological practice helps solve this problem as the method is available, relatively cheap, reproducible and sufficiently precise. It detects viable myocardium in IHD patients with high sensitivity and specificity. Echocardiographically, viable myocardium is marked by increased contractility in one or more segments with initial hypo- and akinesia.
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PMID:[Reversible myocardial dysfunction in patients with ischemic heart disease]. 1236 Jun 11

Apart from heart transplantation for heart failure, the problem arises of which surgical approach should be adopted to treat this disorder. Ischemic heart disease can be surgically managed in three ways: via bypass, the Dor procedure, or by isolated or associated mitral plasty; however, cases of enlarged heart disease can only be surgically treated in two ways: i.e., by mitral plasty, or by the Batista procedure. In cases of ischemic heart disease, the following conditions must be present for coronary bypass: the patients should have an adequate contractile myocardial reserve, that is to say the left ventricle should not be greatly enlarged (< 80 mm in telediastole) or a cardiac output reserve, and there should not be any sign of over-high pulmonary hypertension (an index of > 1.6 or a pulmonary pressure of < 45); an assessment of myocardial viability should then be carried out, mainly based on a thallium fixation at rest and on echographically determined doubtamine-associated stress. In the present study, the mortality rate in a series of 260 patients was 6.3% for subjects aged under 70 years old, with an actuarial survival rate of 82% at one year post-surgery, and of 70% at five years. The Dor procedure can be used in the treatment of dyskinesia, which is now practically non-existent, but also in cases of acute akinesia with resulting left ventricular dysfunction. The aim of this technique is to alter the form of a cavity that has become ovoid to an elliptical form via the insertion of a circular endoventricular patch. The results reported for this technique show an improvement in functional class and ejection fraction. Finally, the technique for repairing mitral failure is more complicated than the two previous methods, as it requires a dynamic assessment of mitral failure, which is best carried out by an evaluation of echographically determined stress. Any mitral failure of ischemic origin of > grade 2 can be corrected during bypass surgery by ring insertion, thereby effecting a simple annuloplasty. On the other hand, the assessment of cases of enlarged heart disease is more complicated, and it is more difficult to carry out palliative surgery. The mitral plasty procedure proposed by Bolling is the technique of choice for patients with severe mitral failure, in general when the ventricle is not too enlarged. However, surgery involving the reduction in size of the left ventricle (the Batista procedure) always includes mitral plasty, and may be performed in patients with a very enlarged ventricle (> 70 mm), in general with moderate mitral failure. These two techniques have been critically assessed both as regards results and when they should be adopted, and their limitations have also been discussed. In conclusion, there are valid surgical alternatives to heart transplantation in cases of heart failure that does not respond to medical treatment, and they should probably be seriously considered before any decision is made to perform heart transplantation. These results appear encouraging, particularly in terms of functional class and left ventricular function, but there are conflicting results for hemodynamic improvement. As regards survival, it is not yet possible to propose prospective randomized trials to compare medical treatment with these surgical techniques. However, further development of these techniques is bound to occur, and an ever-widening gap will exist between the limited number of cases requiring transplantation and the more complex surgical approaches adopted in future, such as permanent circulatory backup or xenografts.
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PMID:[Surgery of heart insufficiency]. 1255 92

Apical hypertrophic cardiomyopathy is a rare form of hypertrophic cardiomyopathy (HCM) recognized by a unique spadelike configuration on the left ventriculogram. Two-dimensional echocardiography is another useful tool in the diagnosis of this condition. The diagnosis may be difficult and may mimic akinesia or apical thrombus in some patients with poor acoustic windows. A 50-year-old woman with typical angina and left ventricular hypertrophy with T wave inversion in leads V3-V6, II, III and aVF is presented. Apical HCM was diagnosed with contrast-enhanced echocardiography and confirmed by finding a spadelike configuration on the left ventriculogram. Apical HCM should be considered in patients in whom symptoms and ECG findings mimic ischemic heart disease. Contrast-enhanced echocardiography is a reliable and simple method in the diagnosis of apical HCM.
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PMID:Apical hypertrophic cardiomyopathy: diagnosis with contrast-enhanced echocardiography--a case report. 1278 33

In patients with coronary artery disease, the presence of left ventricular hypertrophy secondary to hypertension is associated with an increased collateral development. A patient is described who was admitted for myocardial ischemia and severe hypertension. One day after admission, coronary angiography revealed a proximal chronic occlusion of the left anterior descending artery with an extensive collateral vascularization originating from the right and circumflex coronary arteries. In addition, left ventriculography showed antero-apical akinesia that was resolved 5 days later, indicating myocardial stunning. This case illustrates the vulnerability of collateral coronary blood flow to an episode of hypertension, giving rise to myocardial ischemia and even myocardial stunning. This finding advocates aggressive antihypertensive therapy in patients with coronary artery disease and regional myocardial perfusion, which exclusively depends on collateral blood flow.
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PMID:Vulnerability of myocardial collateral perfusion: the impact of episodic hypertension. 1552 74


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