Intra- and interhospital repeatability of radionuclide left ventricular ejection fraction in post-infarction patients.

OBJECTIVE: To evaluate intra- and interobserver and interhospital repeatability of radionuclide left ventricular ejection fraction in post-infarction patients. DESIGN: The study comprised 131 patients who were examined in three different hospitals 2-7 days post infarction. The radionuclide examinations were conducted in a standardized manner, and different observers carried out repeated measurements blind on the stored raw data. RESULTS: The coefficients of variation were between 1.5% and 6.2%, and limits of agreement between +/- 0.012 and 0.056. There were no significant differences between the intra- and interobserver or interhospital repeatability in average, but some significant differences between individual observers were noted. CONCLUSION: The repeatability of LVEF was acceptable, with limits of agreement in the range +/- 0.012-0.056. Some differences between observers and hence hospitals were noted, which may be of clinical relevance.

Epidemiological consequences of introducing new biochemical markers for detection of acute myocardial infarction.

OBJECTIVE: To evaluate how the use of different biochemical markers of myocardial injury affects the recorded numbers of cases of diagnosed acute myocardial infarction (AMI) and unstable angina pectoris (UAP) and also the observed in-hospital mortality of AMI. DESIGN: 442 patients admitted with suspected acute coronary syndrome (ACS) were studied. Based on the World Health Organization (WHO) criteria, the patients were classified into five categories: acute Q-wave myocardial infarction (QMI): acute non-Q-wave myocardial infarction (NQMI); UAP; stable angina pectoris; and chest pain of non-cardiac origin. RESULTS: Using total creatine kinase (tCK) as the "gold standard" for diagnosis, we found 172 AMI. 100 UAP and 170 with other diagnoses. If we used CK-MB (>6 microg/L) or cTnl (> 1 microg/L) for diagnosing AMI, the numbers of AMI increased significantly by 50 (29%) and 64 (37%), respectively. Using tCk, CK-MB or cTnl for diagnosing AMI, the observed in-hospital mortality was 14%, 11% and 10%, respectively. The group of patients with elevated cTnl but negative tCK had similar long-term survival as the group of patients with cTnI >30 microg/L, comprising 95% of the patients with the diagnosis AMI based on tCK. CONCLUSION: The introduction of new biochemical markers for detection of AMI may lead to significant changes in the recorded incidence and in-hospital mortality of AMI. New biochemical markers of myocardial injury must be validated against the traditional markers as they are introduced into clinical practice by the new diagnostic criteria.

[Massive pulmonary embolism--echocardiographic diagnosis and thrombolytic therapy]. / Massiv lungeemboli--ekkokardiografisk diagnostikk og trombolysebehandling.

Thrombolysis is widely accepted as the treatment of choice for acute massive life-threatening pulmonary embolism. Several trials have shown that thrombolytic treatment has reduced morbidity and mortality in this condition, compared to heparin therapy. Rapid diagnosis and treatment start is mandatory for improving the prognosis. Clinical presentation, ECG, arterial blood gas analysis and D-dimer are non-specific tests. Additional tests like ventilation/perfusion lung scan, spiral-computed tomography or pulmonary angiography are needed. In an emergency situation a non-invasive and bedside technique is preferred, and several studies have demonstrated the accuracy of echocardiography in pulmonary embolism. Acute right ventricular overload is indicated by different echocardiographic findings. Three cases with the echocardiographic method as the initial technique for the diagnosis of massive pulmonary embolism are described as well as the treatment consequence and practical administration of thrombolysis. Our patients had presenting features suggestive of massive pulmonary embolism, a clinical situation where an echocardiographic evaluation is appropriate. All presented with typical echocardiographic features. Thrombolytic treatment was initiated immediately after echocardiographic diagnosis. Different thrombolytic regimens were used. Echocardiography may be used as the initial imaging technique for the diagnosis of massive pulmonary embolism. The advantages are obvious, and thrombolytic treatment can be initiated without delay.

Regional differences in hospital admission rates for suspected and verified myocardial infarction in Nord-Trøndelag county, Norway.

OBJECTIVE: To investigate differences in the occurrences of hospitalized suspected and verified acute myocardial infarction (AMI) between the two hospital regions, Namdal and Innherred, within a single county in Norway. DESIGN: A descriptive epidemiological study. SETTING: The county of Nord-Trøndelag in the central part of Norway (131,000 inhabitants). SUBJECTS: Patients admitted for suspected AMI 13 March-11 June 1995. MAIN OUTCOME MEASURES: Proportion of verified AMI among patients admitted. Regional incidence rates for AMI. RESULTS: Among 347 patients admitted to hospitals with suspected AMI, AMI was verified in 120 (35%), corresponding to an annual incidence rate of 509 and 294 per 100,000 (p < 0.001). CONCLUSIONS: Among patients admitted with suspicion of AMI, approximately one third had AMI. The study revealed substantial differences for AMI between two neighbouring hospital regions within one county in Norway. This difference may have implications for the planning and cost of hospital care.

[Troponin T in acute myocardial infarction. Diagnosis and prognosis in patients admitted for suspected acute myocardial infarction]. / Troponin T ved akut myokardieinfarkt. Diagnostik og prognostik hos patienter indlagt til observation for akut myokardieinfarkt.

Cardiac troponin T (TnT) is a new serological marker for use as a diagnostic tool for myocardial damage. A blinded prospective multicentre study representing 298 patients who on admission were suspected of acute myocardial infarction (AMI) to the coronary care units of six Scandinavian hospitals was undertaken to assess the diagnostic performance and prognostic efficacy of a new cardiospecific TnT immunoassay. We used a discriminator value of TnT of 0.20 micrograms/l. One hundred and fifty-five patients (52%) had definite AMI, based on WHO criteria (all had peak S-TnT values > or = 0.20 micrograms/l); 127 patients (43%) had ischaemic heart disease (IHD) without AMI; and 16 patients (5%) had non-IHD (all had peak S-TnT values < 0.20 micrograms/l). The 127 IHD-patients without definite AMI could be subdivided into a group of 44 patients with S-TnT peak values > or = 0.20 micrograms/l, and a group of 83 patients with TnT below this level. A follow-up study was able to define the clinical significance of these findings. The cumulative six months probability of suffering cardiac death or AMI was significantly higher in the subgroup with increased TnT values (14% (6/44)) as compared to the other subgroup (4% (3/83)) (Log-rank test, p = 0.025). The probability of cardiac events was 15% for the patients with definite AMI. We conclude that increased troponin T in serum can detect a subgroup of IHD-patients in whom AMI has been ruled out, but who still have a prognosis as serious as that of patients with definite AMI.

Diagnostic performance and prognostic value of serum troponin T in suspected acute myocardial infarction.

Cardiac troponin T (TnT) is a new serological marker for use as a diagnostic tool for myocardial damage. A blinded prospective multicentre study representing 298 patients suspected of having acute myocardial infarction (AMI), and admitted to the coronary care units of six Scandinavian Hospitals was undertaken to assess the diagnostic performance and prognostic efficacy of a new cardiospecific TnT immunoassay. We used a discriminator TnT value of 0.20 microgram l-1. One hundred and fifty five patients (52%) had definite AMI, based on WHO criteria (all had peak S-TnT values of > or = 0.20 micrograms l-1); 127 patients (43%) had ischaemic heart disease (IHD) without AMI; and 16 patients (5%) had non-IHD (all had peak S-TnT values of < 0.20 microgram l-1). The 127 IHD-patients without definite AMI could be subdivided into a group of 44 patients with S-TnT peak values of > or = 0.20 microgram l-1, and a group of 83 patients with TnT below this level. An equal identification of these patients among the centres was seen (mean +/- SD 35 +/- 13%; range 20-55%). A follow-up study was able to define the clinical significance of these findings. The cumulative 6 months probability of suffering cardiac death or AMI was significantly higher in the subgroup with increased TnT values (14% (6/44)) as compared to the other subgroup (4% (3/83)) (Log-rank test, p = 0.025). The probability of cardiac events was 15% for the patients with definite AMI.(ABSTRACT TRUNCATED AT 250 WORDS)