Amerigo Giordano

Exercise Hemodynamics 1 Month, 2 Months and 1 Year after Myocardial Infarction: Prognostic Considerations1

Sequential electrocardiographic and hemodynamic changes were studied at rest and during symptom-limited bicycle exercise in oligo-asymptomatic patients after myocardial infarction (MI). The exercise tests were performed after the acute episode on days 29 +/- 4 (E1) and 62 +/- 6 (E2) in 128 patients; on days 37 +/- 5 (E1) and 380 +/- 4 (E3) in 97 patients; on days 37 +/- 4 (E1), 72 +/- 6 (E2) and 394 +/- 30 (E3) in 44 patients. All patients underwent an intensive physical training during the second month after the MI. All groups showed a significant increase in work capacity and reduction in heart rate and rate-pressure product at similar work load (E2 and E3 vs. E1). These changes were independent from the level of exercise pulmonary wedge pressure (E-PWP). On the average a reduction of PWP was observed in more compromised patients after training, which became more marked at 1 year. At similar work load 1 year after MI the cardiac index reduced in less compromised patients (E1-PWP greater than 30 mm Hg) while it remained unchanged in patients with E1-PWP less than or equal to 30 mm Hg. Continuation or interruption of the physical training did not seem to affect the hemodynamic evolution. The incidence of ST-segment depression did not change from 1 month to 2 months and 1 year after MI, while both incidence and amount of ST-segment elevation significantly decreased and the sum of R-wave voltages in 12 lead ECG increased at 1 year. In conclusion, oligo-asymptomatic patients, trained and treated by drugs, trend to improve in the first year post-infarct.

Evidence of Residual Ischaemia: Real Danger or Myth?

The extent and severity of residual myocardial ischaemia are well-known as major determinants of mortality after myocardial infarction, and non-invasive assessment of these parameters still plays a critical role in the management of patients. Most of the published data on this topic derive from observations collected before the widespread use of thrombolysis. The results of large multicentre trials assessing the most appropriate therapies after thrombolysis have shown that the more conservative strategy of reserving catheterization and revascularization for patients with recurrent spontaneous or induced ischaemia may be the best approach. Sophisticated techniques to detect more accurately the residual ischaemic burden after infarction have been suggested that would have a major impact on clinical decision making and on the cost of health care. The relative influence of residual ischaemia on the prognosis after myocardial infarction, however, has recently been questioned. The relative risk associated with residual ischaemia seems to be low compared with other predictors of mortality. The progression of coronary artery disease is variable and highly unpredictable, and this may be a major limitation of our ability to predict further ischaemic events.

An automated computerized system for continuous ambulatory pulmonary artery pressure monitoring

To investigate the nature of diurnal and noctural variations of the pulmonary artery pressure, the authors developed an automated analysis system for continuous ambulatory monitoring of the electrocardiographic and pulmonary artery pressure signals. Using the standard Holter technique, the recorded signals are reproduced at 128 times the original recording speed and acquired by a personal computer. An offline program then automatically identifies and executes morphological classification of all recorded heart beats. Heart rate, ST depression, systolic, diastolic, and mean pulmonary artery pressure are then computed on each identified beat, and averaged values of each minute are stored for trend analysis purposes. A subsequent procedure displays ST level, heart rate, and pulmonary artery pressure trends, allowing access to single beat values and waveforms. This system facilitates the assessment of electrocardiographic and pulmonary artery pressure responses of ambulatory patients during daily life.<<ETX>>