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Biomedical subjects

B Dander

Publications and source records attributed to B Dander.

At least 19 recordsLinked to original sources

Isolated noncompaction of the myocardium: an exceedingly rare cardiomyopathy. A case report.

Isolated noncompaction of the left ventricular myocardium is a rare cardiac disorder due to an arrest in myocardial morphogenesis. It is characterized by prominent and excessive trabeculation in a ventricular wall segment, with deep intertrabecular spaces perfused from the ventricular cavity. Echocardiographic findings are important clues for the diagnosis. Clinical symptoms include signs of left ventricular systolic dysfunction even to the point of heart failure, ventricular arrhythmias, and embolic events. We describe an adult case in whom the only clinical symptoms were life-threatening ventricular arrhythmias. Transthoracic echocardiography did not contribute to the diagnosis, which was made thanks to left ventricular contrast angiography. Electrophysiological testing induced a fast monomorphic sustained ventricular tachycardia, with hemodynamic impairment, that was refractory to pharmacological treatment, and for this reason a permanent cardioverter-defibrillator was implanted. A subsequently performed transesophageal echocardiographic examination showed a localized, regional increase in left ventricular wall thickness and degree of trabeculation. The causes and electrophysiological mechanisms of arrhythmias in noncompaction are still unknown: grossly irregular branching and connecting of myocardial fascicles in the noncompacted segments, isometric contraction with increased wall stress, and localized coronary perfusion impairment can all induce disorganized or delayed activation and increase the potential for arrhythmias. This is the first reported case of noncompaction in which an implantable defibrillator was used to control life-threatening arrhythmias.

Adult↗

[The exercise test with atropine].

BACKGROUND: Exercise testing remains the most accessible and widely used technique for the detection of coronary artery disease (CAD) and for the assessment of its severity. Clinical usefulness of the simple exercise test is limited by poor sensitivity and imperfect specificity. Many patients referred for diagnostic stress testing cannot achieve an adequate increase in heart rate due to lack of motivation, poor physical condition, or medications. Atropine increases the heart rate and therefore myocardial oxygen consumption, and might improve the diagnostic accuracy of exercise testing, either reducing the number of non-diagnostic examinations, or increasing the positivity of the test in patients with non severe coronary disease. METHODS: One-hundred-seventy-two consecutive patients (144 males and 28 females, age 58 +/- 8 years) with suspected coronary artery disease underwent exercise testing and coronary angiography. Exercise testing was considered positive in the presence of ST segment depression > or = 0.10 mV horizontal or downsloping, > or = 0.15 mV upsloping, or in the presence of ST elevation without Q waves. The test was considered negative in the absence of significant ST depression or elevation if the exercise heart rate was > 85% of age-predicted maximum, non-diagnostic if the heart rate was < 85%. In 148 patients (86%) coronary angiography showed CAD (> 70% luminal reduction in at least one major vessel), in 24 patients (14%) non significant CAD or angiographically normal coronary arteries (NoCAD). Exercise testing was positive in 134 patients (78%: 85% in CAD, 33% in NoCAD), negative in 13 patients (8%: 3% in CAD, 38% in NoCAD), non-diagnostic in 25 patients (14%; 12% in CAD, 29% in NoCAD). The sensitivity was 85%, specificity was 38%, and diagnostic accuracy 78%. In the 25 patients with non-diagnostic test (18 CAD, 7 NoCAD) the exercise was repeated 30-90 minutes later, immediately after i.v. injection of 1-2 mg of atropine, and was stopped at the same workload of the index test. RESULTS: The atropine-exercise test was well tolerated and accomplished in all cases. The maximal heart rate (139 +/- 11 vs 121 +/- 11) and the double product (25,308 +/- 4082 vs 22,166 +/- 3569) were significantly greater after atropine. The increase of the maximal heart rate improved the detection of the electrocardiographic signs of exercise-induced myocardial ischemia only in CAD patients. In the 18 CAD patients the atropine-exercise test was positive in 8, negative in 5, non-diagnostic in 5. In the 7 NoCAD patients the atropine-exercise test was positive in 1, negative in 6. The test remained non-diagnostic only in 3% of patients. The sensitivity of the test with atropine was 91%, specificity was 63%, and diagnostic accuracy 87%. CONCLUSIONS: The addition of atropine to exercise testing, which causes further chronotropic stress to the myocardium, is well tolerated and safe, and improves the diagnostic accuracy of the test for the detection of coronary artery disease in patients who cannot achieve an adequate exercise heart rate. The combination with atropine increases the utility and the cost-effectiveness of exercise testing.

Atropine↗

[Acute myocardial ischemia: ECG or echocardiography? Considerations on a clinical case].

We present a clinical case and a review of the literature on the usefulness of two-dimensional echocardiography for the diagnosis of acute myocardial ischemia in patients presenting with chest pain but without diagnostic electrocardiographic changes. The case refers to a patient admitted a few hours after an episode of prolonged chest pain without diagnostic electrocardiographic changes, but with a severe wall motion abnormality assessed by two-dimensional echocardiogram. The electrocardiogram obtained 24 hours after admission showed giant negative T waves in the anterior chest leads when the patient was asymptomatic and the echocardiogram showed disappearance of wall motion abnormalities. Coronary angiography demonstrated a thrombotic occlusion of the left anterior descending coronary artery, that was treated by transluminal angioplasty. The considerations refer to the following points: 1) a substantial portion of patients with chest pain examined in the emergency room has initially a normal or non-diagnostic electrocardiogram; 2) in these patients two-dimensional echocardiography provides a highly sensitive and specific noninvasive tool for the establishment of the correct diagnosis of acute myocardial ischemia when a severe wall motion abnormality is shown; 3) if successive amelioration of regional myocardial dysfunction is assessed, this was probably due to stunned myocardium; 4) it is probably not correct to consider T wave inversion as the electrocardiographic equivalent of myocardial stunning, as the two phenomena are not chronologically correlated.

Acute Disease↗

Digital stress-echocardiography using a public domain program for the Macintosh personal computer.

Left ventricular wall motion abnormalities secondary to stress-induced myocardial ischemia can be detected with difficulty by mentally comparing echocardiographic images sequentially recorded on videotape. Digital stress-echocardiography, a combination of ultrasound imaging and digital archiving technologies, at least partially can overcome this problem: the technique is based on reviewing images at rest and after stress (exercise or pharmacological) side by side in dual- or quad-screen digital format, in a synchronized cine-loop, as if obtained simultaneously. This technique however is presently not widely used, due to the high cost of most commercially available systems. We have developed a digital stress-echo system, which is easy to use and relatively inexpensive, running on a Macintosh II personal computer with 8-bit graphics. The 2-D echocardiographic images recorded on videotape are digitized offline using a video digitizing board. The image can be displayed and analyzed using the public domain NIH image software developed by Wayne Rasband, without loss in image quality and resolution, particularly if using Super-VHS videotape. We have made a macro procedure for the montage in a quad-screen format of four digital recorded echocardiographic cardiac cycles of six frames that takes only a little more time than commercially available systems. In conclusion, the use of a personal computer and low-cost software may help to make digital stress-echo techniques more widely feasible in the clinical setting and increase the diagnostic power of the ultrasound technique in the evaluation of patients with known or suspected coronary artery disease.

Coronary Disease↗

[Coronary angioplasty in postinfarct angina].

BACKGROUND: The recurrence of transient myocardial ischemia is a frequent event in the course of acute myocardial infarction. Postinfarction angina develops more frequently after a non-Q wave infarction, and after effective thrombolysis; when uncontrolled by standard medical treatment, it is associated with an increased incidence of unfavorable cardiac events. Therapeutic strategies involve aggressive medical therapy, frequent use of early angiography, and mechanical coronary revascularization with bypass surgery or transluminal coronary angioplasty (PTCA). PATIENTS: We retrospectively examined 68 consecutive patients treated with PTCA for postinfarction angina. Of the whole, 36 (53%) had sustained a non-Q wave infarction; 29 (43%) had been treated with thrombolysis in the acute phase. Ischemia was in the infarction zone in 94% of cases; mean EF was 61.5 +/- 12%, and in 18 cases EF was < 55%. RESULTS: In 7 cases two arteries were dilated. There were no deaths related to the procedure. The overall success rate was 91.2%. Major complications occurred in 2 cases (1 acute occlusion with reinfarction, 1 major dissection requiring emergency surgery). The results are analyzed according to the time interval between index infarction and PTCA. In 28 cases (Group A) PTCA was performed within 30 days due to medically refractory symptomatology; in 40 cases (Group B) PTCA was postponed to beyond 30 days from infarction. In Group A involvement of the left anterior descending coronary artery was more frequent (75% of cases vs 40%; p = 0.009). The success rate in Group A was slightly lower than for Group B (85.7% vs 95%); the incidence of complications was higher (7.1% vs 0%), although not statistically different. At 6 month follow-up a restenosis was found in 10 cases (16% of successful PTCAs, 21% of angiographic controls). CONCLUSIONS: We conclude that for patients with postinfarction angina, selected for a suitable coronary anatomy, PTCA is an effective therapeutic option, with a high success rate, low immediate morbidity, and good mid-term results. The risk of intraprocedural complications appears only slightly higher for patients with unstable symptoms, who undergo PTCA earlier after infarction.

Adult↗

[Angiographic morphology of coronary lesions in various syndromes of ischemic cardiopathy].

The angiographic morphology of coronary lesions is often completely ignored in the prognostic and decision-making process related to patients with coronary disease. We performed this study to evaluate the possibility of identifying complex or complicated atherosclerotic lesions by means of routine diagnostic coronary arteriography, and to assess their prevalence in the different syndromes of ischaemic heart disease. From an overall group of 200 successive cases studied using coronary angiography, 111 patients with significant coronary artery disease in whom a "culprit lesion" could be identified were retrospectively selected. The angiographic morphology of coronary lesions was defined according to an original classification as: 1) simple stenosis, 2) complex lesion, 3) thrombosis. Of the 111 patients, 36 had been studied for stable angina, 31 for unstable angina, 10 for a non-Q wave myocardial infarction, 34 for transmural infarction. The clinical groups did not show any significant differences when compared on the basis of number of vessels involved and degree of narrowing of the ischaemia-producing artery. Significant differences were found when angiographic morphology was analyzed. In stable angina 78% of ischaemia producing lesions appeared as simple stenoses, while 92% of the unstable or more severely ischaemic patients exhibited complicated lesions (p less than 0.001). In unstable angina and non-Q infarction a complex lesion was present respectively in 71% and 60% of the cases; clear-cut intraluminal thrombosis was demonstrated in 23% of unstable angina, in 30% of non-Q wave infarction and in 39% of transmural infarction (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[The diagnosis of prosthesis pathology in biological and mechanical valves. I. Clinical and echocardiographic evaluation].

We retrospectively evaluated the clinical and echocardiographic findings of 50 patients with documented malfunctioning of cardiac prosthetic valves. The prostheses, mechanical or biological, were in 24 cases in a mitral and in 26 cases in an aortic position. Prosthetic dysfunction was due to thrombosis, fibro-calcific degeneration, fibrous cloth, bacterial infection, dehiscence, mismatch. The clinical features were represented by cardiac insufficiency of different degrees, up to global congestive failure unresponsive to medical treatment, by sudden low-output syndrome, arrhythmias, angina. The changes in auscultatory findings have appeared important clues to prosthetic malfunction, but we stress the necessity of an instrumental documentation of the type and grade of dysfunction. Echocardiography has represented an essential tool for a rapid and accurate noninvasive diagnosis of prosthetic pathology. The echocardiographic examination, except 2 false negatives, has consistently provided informations useful for therapeutic decisions. In 7 cases in critical clinical conditions (refractory heart failure or shock) the echocardiographic examination has afforded the exact documentation and identification of prosthetic pathology, allowing by itself a surgical decision.

Aortic Valve↗

[Prosthetic pathology of mechanical and biological valves in the mitral and aortic position. II. Hemodynamic-angiographic evaluation and anatomo-surgical aspects].

The catheterization parameters of 42 patients with surgically confirmed prosthetic valve malfunction were retrospectively analyzed in order to evaluate the role of hemodynamic and angiocardiographic examination in the diagnosis of prosthetic complications. The invasive investigation provided in all cases more precise informations regarding the type and grade of prosthetic malfunction as compared to noninvasive techniques. Transvalvular gradients could be quantified, the amount of regurgitation could be defined and associated lesions (paraprosthetic aneurysms, aortic root dissection, fistulas secondary to bacterial endocarditis) could be recognized. The surgical exploration confirmed prosthetic malfunction in all cases except two, with fibrous tissue ingrowth: at the moment this complication is not distinguishable from thrombosis and no specific diagnostic signs have been described either with invasive or noninvasive techniques. In our experience the patients who can benefit from hemodynamic examination are: patients with echocardiographic examination of poor technical quality, patients in whom noninvasive investigations can not completely explain the clinical status ("false negative" echocardiograms, multiple prosthetic valves), all cases in whom cardiac surgery requires a precisely detailed evaluation of the prosthetic malfunction. The opportunity or necessity to perform an invasive study in patients with clinically suspected or proven prosthetic malfunction should be discussed individually.

Angiocardiography↗

[The pressure-dimension curve and midwall stress. Use of a combined hemodynamic-echocardiographic method and correlation with contrast ventriculography].

An invasive (left ventricular pressure recording) and a noninvasive technique (M-mode echocardiography) were combined during the hemodynamic study of 15 patients with various degrees of left ventricular impairment, in order to provide left ventricular function parameters independent from contrast studies. Left ventricular pressure, dimension and wall thickness changes were continuously digitized on a computer system, which was able to derive the ventricular pressure-dimension loop and to calculate the midwall equatorial stress at end-diastole and peak-systole. The parameters derived from the loop (diastolic work, net systolic work, cycle efficiency) and midwall meridional and circumferential stresses were compared with the results of contrast ventriculography and with the wall hypertrophy index. Diastolic work appeared to be correlated with the systo-diastolic volume change; systolic work correlated with the ejection fraction; the cycle efficiency was inversely correlated with both end-diastolic and end-systolic volumes and directly correlated with the hypertrophy index. Midwall stress, both end-diastolic and peak-systolic, was strongly and positively correlated with ventricular volumes, while it decreased with increasing hypertrophy. Systolic stress increased with decreasing ejection fraction. The combined echo-pressure technique, through the evaluation of the pressure-dimension loop and the calculation of wall stress, can generate data of left ventricular function that allow a more complete assessment of left ventricular impairment.

Adolescent↗

Diagnosis of cardiac amyloidosis made by ultrastructural examination of endomyocardial biopsy. A case report.

A case of cardiac amyloidosis is described in which clinical and scintigraphic findings were those of ischemic heart disease. Electrocardiogram disclosed low voltages in the peripheral leads and a pattern of anterior pseudo-myocardial infarction. 2D-echocardiography showed thickened cardiac walls and a "granular sparkling" appearance of the septum. The curve of the left ventricular diastolic pressure suggested impaired ventricular relaxation without a true dip-plateau morphology. Stains for amyloid of rectal biopsy specimens were negative. Histological study of left ventricular endomyocardial biopsy indicated the presence of basophilic material among the myocytes; at ultrastructural examination this infiltrating substance resulted to be amyloid. This case stresses the effectiveness of ultrastructural investigation of left ventricular endomyocardial biopsy in the diagnosis of infiltrative and/or metabolic cardiac disorders.

Amyloidosis↗

Effects of the cold pressor test on the left ventricular function of patients with coronary artery disease.

We used the cold pressor test as provocative of myocardial ischemia in 23 subjects evaluated for chest pain on effort. Seven of them (group N) had normal coronary arteries, and 16 (group CAD) had critical stenoses along the main branches of the left coronary artery. In both groups exposure to cold induced increase in arterial pressure and double product. Left ventricular end-diastolic pressure increased +60% from baseline (P less than 0.001). Angiocardiographic parameters, unchanged in group N, showed an impairment of left ventricular function in group CAD. End-diastolic volume increased +11% (P less than 0.01), ejection fraction decreased -8% (P less than 0.0025), with a significant reduction in segmental wall motion in the area of the diseased artery (P less than 0.001). The mean Vcf was slightly and not significantly reduced, while early-systolic and end-diastolic stress and the constant of stiffness consistently increased in both groups. The appearance or extension of ventricular wall contraction abnormalities in group CAD, in the absence of demonstrable coronary spasm and in the presence of a remarkable increase in left ventricular end-diastolic pressure and stress, was interpreted as due to ischemia secondary to increased extravascular resistances to coronary flow. The cold pressor test is proposed as a useful tool for the diagnosis and evaluation of patients with ischemic heart disease.

Adult↗