[On the possibility of accelerating thrombolytic therapy in the acute phase of myocardial infarction: efficacy of and tolerance to the infusion of 1.5 million units of streptokinase in 30 minutes]. / Sulla possibilità di velocizzare l'intervento trombolitico nella fase acuta dell'infarto miocardico: efficacia e tollerabilità dell'infusione di 1.5 milioni di unità di streptochinasi in 30 minuti.

To evaluate efficacy and tolerability of the systemic infusion of 1,500,000 streptokinase units in 30', we treated 26 consecutive patients with acute myocardial infarction within 3 hours of the onset of chest pain. They were 23 men and 3 women, mean age was 59 +/- 8 years. None of them had a history of previous myocardial infarction. From clinical and electrocardiographic data, as well as from creatine kinase curves, we assumed myocardial reperfusion in 19 patients (73%). Within 30' after infusion, thrombin time increased to more than 300" in 25/26 patients (96%). Streptokinase induced hypotension (which we defined as a decrease in systolic blood pressure of more than 30 mmHg) in 13 patients (50%), and in 5 of them (19%) systolic blood pressure fell below 90 mmHg. Hypotension was counteracted by adopting the Trendelenburg position in 7 patients, and by an intravenous infusion of atropine in 5. In the remaining patient, streptokinase infusion was slowed down. Due to these interventions, a non-significant decrease in systolic blood pressure was observed from 129 +/- 26 to 112 +/- 20 mmHg at the end of the infusion. Streptokinase-induced hypotension was not predicted either by clinical, or electrocardiographic, or chest X-ray film data, or laboratory findings. No other side-effects occurred. Hence, the infusion of 1,500,000 streptokinase units in 30' in the acute phase of myocardial infarction is active, and well tolerated. It must be emphasized, however, that during the infusion, hypotension occurs frequently and unpredictably, sometimes reaching alarm levels. This makes the monitoring of systolic blood pressure imperative during streptokinase infusion.

Exercise radionuclide ventriculography after uncomplicated myocardial infarction: what could we gain from the analysis of LVEF throughout the whole test?

To assess the usefulness of a step by step evaluation of exercise left ventricular ejection fraction (LVEF), 219 consecutive patients with recent uncomplicated myocardial infarction and 30 normal subjects underwent a symptom-limited cycloergometer test followed by exercise radionuclide ventriculography (ExRNV). LVEF was monitored throughout the whole test. 49 patients underwent coronary arteriography for clinical reasons. 5 patterns of exercise LVEF could be observed: progressive increase: 55 patients (25%) and 27 normal subjects (90%); progressive decrease: 37 patients (17%); initial increase followed by significant decrease: 54 patients (25%); lack of initial modification and terminal decrease: 35 patients (16%); no modification: 38 patients (17%) and 3 normal subjects (10%). Grouping the patients in this fashion allowed us to increase the specificity of ExRNV from 70% to 100%, without loss of sensitivity (95%). As for the patients in subgroup C, 32/54 showed unequivocal ECG ischaemic changes, occurring simultaneously with LVEF decrease; in 33/54 LVEF dropped during the last workload; in 25/54 the last stage LVEF was equal to or higher than the basal LVEF. The statistical analysis showed that ischaemic ECG changes (P less than 0.0001), exercise-induced wall-motion abnormalities (P less than 0.0001), and the presence of multivessel coronary artery disease (P less than 0.0001) were significantly more frequent in patients showing patterns (b)-(d), which should be considered as ischaemic. Our method allowed the unequivocal identification of ischaemic patterns in LVEF during exercise, which might be missed if only its basal and final values are considered.

[Effects of isometric exercise on the right ventricular function and on the pulmonary circulation, in normal subjects (author's transl)]. / Effetti dell'esercizio isometrico sulla funzione del ventricolo destro e sull'emodinamica polmonare in soggetti normali.

The pulmonary circulatory response and right ventricular haemodynamics were assessed in normal subjects who sustained hand-grip exercise (HG) at 50% of the maximum voluntary contraction (M.V.C.) for 3 minutes. Ten normal subjects, aged 25 to 66 years, who underwent full right catheterization were studied. The following parameters were taken into consideration: heart rate (HR), end diastolic right ventricular pressure (EDRVP) end diastolic right ventricular volume (EDRVV), mean pulmonary arterial pressure (PAP), pulmonary wedge pressure (PWP), total pulmonary resistance (TPR), cardiac output (CO) and right ventricular sistolic work minute index (RVSWMI). These data were obtained by means of a tip-micromanometer connected with an polygraphic recorder and by means of thermodilution cardiac output computer. The statistical significance of the difference between the resting control values and those after isometric exercise was calculated with the Student's paired t test. A comparison of the control data with those obtained after isometric exercise, demonstrate a statistical significant (p less than 0,001) increase of the HR, PAP, PWP, TRP, CO, RVSWMI, a less significant (p less than 0.01) increase RVEDP. Our findings show that the HG causes changes in the pulmonary circulation and the right ventricular function. Our data seem to sustain that the pulmonary circulation respondes differently under isometric stress than it does under isotonic stress. The use of HG can thus be postulated as a useful means of evaluation of the response of the pulmonary circulation and right ventricular function.