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G Stix

Publications and source records attributed to G Stix.

At least 55 records · Page 3Linked to original sources
PubMed1994

Power medicine.

Explore the source record for details and available documents.

Administration, Cutaneous↗
PubMed1993

Progressive decrease in myocardial ischemia assessed by intracoronary electrocardiogram during successive and prolonged coronary occlusions in angioplasty.

Progressive decrease in chest pain and surface ECG changes are commonly observed during successive balloon inflations in coronary angioplasty, which suggests a decrease in myocardial ischemic response. To assess this hypothesis, we continuously recorded intracoronary ECGs during four balloon inflations; each of the inflations was maintained to a minimum of 120 seconds in 19 patients who had significant stenosis in the left anterior descending artery and normal left ventricular function. Three successive QRS-T complexes were analyzed on surface and intracoronary ECGs for measurements of ST-segment elevation 60 milliseconds after the J point. Surface ECG changes were compared with intracoronary ECG changes. On intracoronary ECG, ST area (in square millimeters) and T wave amplitude (in millimeters) were also computed. Chest pain was noted as present or absent during each successive balloon inflation. Ability of intracoronary ECG to detect myocardial ischemia, which was defined as ST-segment elevation greater than 1 mm during balloon inflations 1 to 4, was 89%, 89%, 84%, and 74%, respectively and was higher than that of surface ECG, which was 68%, 63%, 68%, and 58%, respectively. On intracoronary ECG, when compared with the first balloon inflation, a significantly smaller increase in ST-segment elevation was noted during each subsequent balloon inflation, whereas a significantly smaller increase in ST area and T wave amplitude was noted only during balloon inflation 4. The number of patients who experienced chest pain decreased from 15 to 13, 10 and 6 from the first to the fourth balloon inflation. This report demonstrates a progressive decrease in myocardial ischemic response during successive and prolonged balloon occlusions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Improved myocardial ischemic response and enhanced collateral circulation with long repetitive coronary occlusion during angioplasty: a prospective study.

OBJECTIVES: The goal of the study was to evaluate the progressive increase in ischemic threshold with multiple sequential transient coronary occlusions and to assess the role of the collateral circulation in adaptation to ischemia. BACKGROUND: It has been observed that the duration of balloon inflations during coronary angioplasty can be gradually prolonged during subsequent dilations with a reduction in patient symptoms and diminished ischemic electrocardiographic (ECG) changes. Although the mechanism has not been fully explained, recruitment of coronary collateral circulation induced by repeated coronary occlusion has been reported. The stimuli for recruitment and the natural history of coronary collateral circulation are not understood. METHODS: Seventeen patients with isolated stenosis of the left anterior descending coronary artery and a normal left ventricle were enrolled. Angioplasty consisted of five successive prolonged inflations. Sequential changes in clinical, intracoronary ECG and left ventricular indexes of myocardial ischemia were examined. Coronary collateral channels were evaluated during balloon inflations by ipsilateral and contralateral injections of contrast medium and hemodynamically by occlusion pressure. RESULTS: An improved tolerance to myocardial ischemia with repetitive coronary occlusions was demonstrated by a significant reduction of angina, ST segment deviation, left ventricular filling pressure and less impairment of ejection fraction. Left ventricular wall motion abnormalities remained unchanged. Collateral angiographic grade did not change in 7 patients and increased in 10. CONCLUSIONS: This study confirms a progressive adaptation of myocardial ischemia to repetitive coronary occlusions and supports the concept that sequential episodes of myocardial ischemia are a stimulating factor for the recruitment of collateral channels in humans. These results also suggest that enhancement of recruitable collateral circulation might be an underlying mechanism of myocardial ischemic preconditioning.

Adult↗
PubMed1991

Acute and long-term efficacy of propafenone in patients with sustained ventricular tachyarrhythmias: assessment with programmed ventricular stimulation.

To determine the electrophysiological properties of oral propafenone, 50 patients (39 male and 11 female, aged 31 to 80 years) with sustained ventricular tachycardia or ventricular fibrillation underwent serial electrophysiological drug testing, using propafenone (750 to 900 mg daily) as the anti-arrhythmic regimen of first choice. During baseline study, all patients had inducible sustained ventricular tachyarrhythmias. After oral loading of propafenone, 37 patients (74%) remained inducible whereas 13 were rendered non-inducible. Among the still inducible patients, the mean VT rate decreased from 223 +/- 38 b.min-1 (baseline) to 172 +/- 32 b.min +/- 1 (P less than 0.001). Four patients showed an increase of VT rate during propafenone compared to the VT rate at control. Non-inducible patients were discharged on propafenone. During a mean follow-up period of 20 +/- 15 months, there were three non-fatal VT recurrences among the responders, two of them due to non-compliance. Thus, propafenone used as the anti-arrhythmic agent of first choice among patients undergoing serial electrophysiological drug testing for ventricular tachyarrhythmias proved effective in suppressing VT induction in 26%. With regard to arrhythmic events, these patients have a favourable outcome.

Administration, Oral↗