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BACKGROUND The present study was designed to evaluate the efficiency of a newly developed troponin T enzyme immunoassay for the detection of acute myocardial infarction. METHODS AND RESULTS The study comprised 388 patients admitted with chest pain and suspected myocardial infarction and 101 patients with skeletal muscle damage and additional suspected myocardial cell damage. Troponin T was elevated to more than twice the analytical sensitivity of the assay (0.5 microgram/l) in all patients with non-Q wave (range, 1.2-5 micrograms/l) and Q wave infarction (range, 3-220 micrograms/l). Troponin T appeared in serum as early as 3 hours after onset of pain in 50% of the patients and remained elevated in all patients for more than 130 hours, revealing release kinetics of both free cytosolic and structurally bound molecules. The diagnostic efficiency of troponin T was superior to that of creatine kinase-MB (98% versus 97%) and remained at 98% until 5.5 days after admission, if patients with unstable angina were excluded from analysis. In the 79 patients with unstable angina, troponin T was elevated (range, 0.55-3.1 micrograms/l) in at least one blood sample from each of 37 patients (56%). Circulating troponin T was correlated to the presence of reversible ST segment or T wave changes on the electrocardiogram (p less than 0.005) and to the frequency of in-hospital complications. In the 101 patients with skeletal muscle damage and suspected additional cardiac muscle damage, troponin T was the most useful test; its efficiency was 89% or 94% (depending on the discriminator value used) as compared with 63% for creatine kinase-MB. CONCLUSIONS Thus, the data of the study indicate that the newly developed troponin T test improves the efficiency of serodiagnostic tools for the detection of myocardial cell necrosis as compared with conventionally used cardiac enzymes.

We report on a 44-year-old male with primary cardiac angiosarcoma who died 11 months after onset of nonspecific symptoms (thoracic pain and general fatigue) of intracerebral metastases. A right atrial tumor mass and a pericardial effusion could be demonstrated by transthoracic and transesophageal echocardiography. Cardiac angiography showed a right atrial hemangioma, fed by the right coronary artery. In a review of 108 cases of primary cardiac angiosarcoma we summarize clinical features, diagnostic means, therapeutic approaches and life expectancy of this rare disease.

Troponin T is a unique cardiac antigen which is continuously released from infarcting myocardium. Its cardiospecificity as a marker protein might be particularly useful in assessing myocardial cell damage in patients undergoing cardiac surgery. Therefore, circulating troponin T was measured in serial blood samples from 56 patients undergoing cardiac surgery and in two control groups--22 patients undergoing minor orthopaedic surgery and 12 patients undergoing lung surgery by median sternotomy. In both control groups no troponin T could be detected, whereas activities of creatine kinase were raised in all 12 lung surgery controls and activities of the MB isoenzyme were raised in five of the 12 patients in the lung surgery group and in four of the 22 patients in the orthopaedic surgery group, respectively. All the patients undergoing coronary artery bypass grafting (n = 47) and cardiac surgery for other reasons (n = 9) had detectable concentrations of troponin T. Five patients had perioperative myocardial infarction detected as new Q waves and R wave reductions. In these five patients troponin T release persisted and serum concentrations (5.5-23 micrograms/l) reached a peak on the fourth postoperative day. In the 51 patients without perioperative myocardial infarction serum concentrations and the release kinetics of troponin T depended on the duration of cardiac arrest. In patients in whom aortic cross clamping was short troponin T increased slightly on the first postoperative days; in patients with longer periods of aortic cross clamping troponin T concentrations were higher and remained so beyond the fifth postoperative day. In patients with non-specific changes on the electrocardiogram troponin T concentrations were significantly higher on days 1 and 4 after operation than in patients with normal postoperative electrocardiograms(11.2 (5) and 4.5 (2.6) v 8.2 (3.4) and 2.9 (1.6) 1microg/l). Serum concentrations of troponin T showed some myocardial cell damage in every patient undergoing cardiac surgery. The persistent increases that were more common in patients with longer periods of cardiac arrest must have been caused by damage to the contractile apparatus. These results suggest that perioperative myocardial cell necrosis may be more common than indicated by changes of the QRS complex on the electrocardiogram.

Infarct size can be estimated noninvasively by analysis of circulating CK-MB and/or cardiac myosin light chains. To investigate whether myosin light chains release is correlated with the impairment of left ventricular function in acute myocardial infarction, this marker protein was determined by liquid phase radioimmunoassay in serial blood samples of 25 patients. Likewise CK-MB was measured in the same blood samples. From the serum concentration changes the cumulative appearance was calculated as an estimate of infarct size. Left ventricular enddiastolic pressure, global and regional ejection fraction were measured immediately and 3 weeks after admission. Particularily during the chronic phase of myocardial infarction a close correlation was found between serological estimates of infarct size and impairment of left ventricular function. The cumulative appearance of myosin light chains was superior to CKMB in assessing the hemodynamic impact of myocardial infarction in the acute and chronic stage. Therefore, myosin light chains are an appropriate serological indicator for the hemodynamic significance of myocardial infarction during the acute and chronic stage and might allow an assessment of the patients' risk.

Nach dem Ergebnis der tierexperimentellen Synchronisationsversuche ist festzustellen, das eine „mechanische Kopplung“ von Vorhofund Kammeraktion sowohl am isolierten Froschherzen als auch am Saugetierherzen in situ als gesichert gelten kann. Die Adaptation der Sinusfrequenz an die Kammerfrequenz erfolgt am Ganztier offenbar nicht durch unmittelbare mechanische Einwirkung der heterotopen Ventrikelerregung auf den Sinusknoten, sondern indirekt uber eine Vorhofkontraktion gegen geschlossene AV-Klappen. Die am Kaltbluterherzen beobachtete, durch ausschlieslich elektrische Leitung bedingte Rhythmenverknupfung, die nach physikalisch-technischen Modellversuchen auch am Warmbluterherzen eine Rolle spielen konnte, lics sich bisher am Ganztier nicht bestatigen.

A coronary artery-to-left ventricular fistula is a rare finding; to the best of our knowledge, a total of only 35 cases have been reported. Only 5 cases of a generalized arterio-systemic fistula with three vessel involvement have been reported in the literature. We describe another case involving all major coronary arteries. A review of the literature is presented and the data of the reported cases are analyzed. A 55 year old woman was examined because of recurrent chest pain which had persisted for 2 years. On physical examination, the only abnormal finding was a fourth heart sound. Exertional chest pain, a positive exercise stress test, and the results of a lactate extraction study suggested severe myocardial ischemia. Thallium myocardial scintigraphy showed no evidence of a perfusion defect. Cardiac catheterization revealed an irregular left ventricular endocardial pattern (Thebesian veins). Selective coronary angiography showed communicating fistulae of all three major coronary arteries with the left ventricular cavity. We assume that this vascular anomaly causes a coronary steal phenomenon and subsequent myocardial ischemia.

To detect myocardial cell damage, serum samples of 42 consecutive patients with angina at rest were screened for cardiac myosin light chains, which were detected in 22 patients (52%). In 17 of these patients there was a persistent release of myosin light chains lasting until the 4th hospital day, whereas in 7 patients myosin light chains were only detectable during the initial 24 h after admission. The presence of myosin light chains correlated with signs of ischemia in the electrocardiogram (ECG) (p less than 0.05) and with the extent of coronary artery narrowing (p less than 0.05). Cardiac myosin light chains were elevated in serum only if there was a greater than or equal to 75% diameter narrowing in at least one major vessel. In all five patients who developed transmural myocardial infarction during the course of their hospital stay, myosin light chains were detectable greater than or equal to 28 h before the diagnosis of myocardial infarction could be established by ECG criteria and conventional serum enzymes. Thus the detection of circulating cardiac myosin light chains enables one to identify a subgroup of patients with angina at rest having more severe coronary artery disease with a worse outcome.

Hypertrophic cardiomyopathy (HCM) has various manifestations with respect to the localization of the hypertrophy. In this study we report clinical, electrocardiographic (ECG), echocardiographic (echo), and hemodynamic findings in midventricular obstruction (MO), an uncommon form of hypertrophic obstructive cardiomyopathy (HOCM) in 9 patients. The prevalence of systolic anterior motion of anterior mitral leaflet (SAM) in MO, an echocardiographic diagnostic hallmark in HOCM, was another purpose of this study. All patients had complete clinical, ECG, echo, and hemodynamic workup, including left ventricular (in 4 patients simultaneous biventricular, SBVA) and coronary angiograms. All patients had dyspnea and palpitations, chest pain, 2 had syncope. In the ECG, atrial fibrillation was present in 2, and left ventricular hypertrophy in 9 patients. Septal and left ventricular free wall thickening was significantly present in all patients in echo, and SAM in 1 patient. The intraventricular gradient (IVG) was 40-176 mmHg, in 1 case 40 mmHg by provocation, Brockenbrough was positive in all patients. Two patients had right ventricular IVG. A positive beta-blocking agent effect was present in 6 cases. The best localization of the obstruction was possible with SBVA and 2D-echo. We conclude that MO has all the signs of HOCM, but SAM in echocardiography is uncommon. SAM is occasionally present and is not a necessary factor to produce an intraventricular pressure gradient in HOCM, especially in MO. It seems that hypertrophic right ventricular obstruction is relatively common in MO (2 of 9 cases), and may have the same obstructive mechanism.