Presence Of ST-segment Depression Research Articles

Exercise testing? Not at all.

The traditional approach to the ambulatory patient with suspected or definite coronary disease is to evaluate the clinical features, to perform non-invasive tests for myocardial ischaemia, and to proceed, if necessary, to coronary angiography and coronary revascularisation. However, when the results of the exercise tests are discordant with the clinical classifications they are usually misleading as diagnostic tools. When the exercise test is used to assist prognostication, the information provided overlaps with that available to the clinician and only the presence of ST segment depression is an independent prognosticator. The amount of ST segment shift has been found to be an inferior prognosticator to the severity of disease seen on a coronary angiogram and the latter allows for appropriate decisions to be made regarding coronary angioplasty or bypass surgery. A more appropriate use of exercise testing is as a gate for coronary angiography if there is real doubt or the nature of the chest pain or as an aid in therapeutic decisions if the coronary angiography interpretation is difficult.

ST Segment Depression in Right-Sided Electrocardiographic Leads in Patients With Acute Myocardial Infarction

The presence of ST segment depression in right-sided electrocardiographic leads has been infrequently reported in the literature. We report the cases of two patients with anterolateral and posterior myocardial infarctions with ST segment depression in right-sided electrocardiographic leads. We hypothesize that this electrocardiographic change is a reciprocal expression of ST segment elevation of the opposing left ventricular wall.

Effects of a short-term training programme in post-infarct patients with residual myocardial ischaemia.

To study prospectively haemodynamic changes after a four-week period of physical training in post-infarct patients with exercise-induced myocardial ischaemia, a maximal symptom-limited ergometric test in the supine position with electrocardiographic and haemodynamic monitoring was carried out in 46 males (mean age: 53 +/- 8 years) during drug wash-out 35 +/- 15 days after acute myocardial infarction (E1), and again after 31 +/- 3 days of physical training (E2). The infarction site was inferior in 38 patients (83%), anterior in seven (15%) and anterior + inferior in one (2%). After physical training none of the resting parameters were significantly changed. During exercise, working capacity increased from 6525 +/- 3314 to 8853 +/- 4342 kpm (P less than 0.001) together with cardiac output and arterio-venous 02 difference, while stroke volume and pulmonary wedge pressure (PWP) remained unchanged. At matched work load a significant reduction was observed in heart rate (HR) (128 +/- 18 vs. 122 +/- 17 beats min-1, P less than 0.001) and PWP (23 +/- 8 vs. 21 +/- 8, P less than 0.05). The extent and presence of ST-segment depression in standard ECG at E1 was not indicative of a different haemodynamic pattern or of a different response to training. During E1, 23 patients had an ischaemic threshold greater than 2700 kpm. When compared with the 23 patients with an ischaemic threshold less than or equal to 2700 kpm, they had a greater work capacity (8409 +/- 3045 vs. 4798 +/- 2552 kpm, P less than 0.05) and a lower PWP at peak exercise (19 +/- 8 vs. 27 +/- 6 mmHg, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Occurrence of anterior ST depression in inferior myocardial infarction and relation to clinical outcome.

In 229 patients admitted to the coronary care unit (CCU) at Sahlgren's Hospital developing inferior myocardial infarction, and with no previous myocardial infarction, the clinical outcome was related to the presence of ST-segment depression in 16 anterior chest leads. In all, 64% had anterior ST-segment depression. These patients differed from those not having ST depression in several aspects. They had larger infarcts, as assessed by serum enzyme activity and ECG recording. They were more prone to congestive heart failure and required more treatment for this complication. Their intensity and duration of pain during the first 4 days appeared to be more substantial. During a 5-year follow-up, patients with anterior ST depression tended to have a higher mortality. We conclude that among patients with inferior myocardial infarction and no previous infarction, those with anterior ST-segment depression form a subgroup with a more severe clinical course.

Accurate detection of triple vessel disease in patients with exercise induced ST segment depression after infarction.

The severity of coronary artery disease is an important determinant of prognosis after acute myocardial infarction. The ability of a symptom limited exercise test to predict the presence of triple vessel disease was assessed in 221 patients three weeks after infarction. Coronary angiography was performed in patients with exercise induced ST segment depression. The presence of ST segment depression alone was poorly indicative of triple vessel disease; however, some specific features of ST segment changes on exercise were of predictive value. Downsloping ST segment configuration alone or horizontal ST segment depression associated with an early onset and a late recovery time after exercise correctly identified 30 (90%) of 33 patients with triple vessel disease whereas it incorrectly identified only 6 (15%) of 39 patients with single and double vessel disease. An abnormal blood pressure response was also predictive. In patients with ST segment depression after infarction triple vessel disease can be detected accurately by a combination of the electrocardiographic and haemodynamic variables attained on exercise.

Dipyridamole-echocardiography test in patients with exercise-induced ST-segment elevation

Fourteen consecutive patients with exercise-induced ST-segment elevation in the absence of previous infarction and basal left ventricular asynergy at rest performed a dipyridamole test (infusion of dipyridamole, 0.14 mg/kg/min intravenously for 4 minutes) during 12-lead electrocardiographic (ECG) and 2-dimensional echocardiographic monitoring. In 7 of the 14 patients, dipyridamole infusion consistently induced ST-segment elevation in the leads that showed ST elevation on effort; reversible asynergy (occurring in the region corresponding to the ECG leads with diagnostic changes) could always be documented by echocardiography. In 2 patients dipyridamole induced reversible asynergy in presence of ST-segment depression. In these 9 patients angiography invariably revealed a severe organic stenosis in the coronary artery feeding the region that became transiently asynergic after dipyridamole. In the other 5 patients (all of whom had either spontaneous or ergonovine-induced ST-segment elevation), the dipyridamole test yielded no significant echocardiographic or ECG change; coronary angiography showed absent (2 patients) or significant (3 patients) coronary artery disease. In conclusion, dipyridamole may induce transmural ischemia in humans, as detected by the electrical hallmark of ST elevation; this ECG pattern, in contrast to ST depression, reliably predicts the presence and site of transient regional asynergy. When dipyridamole induces ST-segment elevation, severe basal stenosis is invariably present in the coronary artery supplying the transiently asynergic myocardial region.

Ventricular premature complexes in prognosis of angina.

We studied the prognostic role of ventricular premature complexes occurring during 1 hour of electrocardiographic monitoring of 416 men with effort angina who had never had myocardial infarction, and compared mortality over 5 years with that of 1739 men with infarction before first observation. Multivariate analyses of survival identified the presence of ventricular premature complexes in 1 hour of monitoring, the presence of ST-segment depression on the standard ECG, and age as the variables making the most important independent contributions to risk of death (all causes and sudden coronary deaths) among the men with angina. The relatively lower age-adjusted 5-year mortality among men with angina compared with those who had a prior myocardial infarction reflects the lower prevalence in the former group of indicators of myocardial dysfunction, such as ventricular ectopic activity and ST-segment depression.