Biomedical subjects

A Manginas

Publications and source records attributed to A Manginas.

24 records · Page 2Linked to original sources

PubMed1997

Coronary vein flow velocity changes during transluminal balloon angioplasty: a study using the Doppler guide wire.

The coronary flow velocity changes in the great cardiac and middle cardiac veins, induced by intracoronary administration of nitroglycerine, adenosine, and during percutaneous transluminal coronary angioplasty, were evaluated in 12 patients with significant coronary stenoses, using the Doppler wire (Flowire). Optimal spectral signals of the time-averaged peak flow velocity were obtained in 10 patients. Nitroglycerine produced no significant flow velocity changes (P = 0.13). Adenosine caused a significant augmentation of flow velocity compared to baseline (P = 0.003). During balloon inflation, venous flow velocity decreased (P = 0.007); however, the venous outflow did not cease. A pronounced venous hyperemic response, following balloon deflation, was also documented. The utility of continuous vein flow velocity monitoring with the Flowire, during high-risk and complicated coronary interventions remains to be elucidated.

Adenosine↗

PubMed1996

Coronary flow velocity changes after intravenous dipyridamole infusion: measurements using intravascular Doppler guide wire. A documentation of flow inhomogeneity.

OBJECTIVES: This study assessed changes in coronary flow velocity measured distal to a significant stenosis of the left anterior descending coronary artery and at the adjacent normal left circumflex coronary artery, produced by intravenous administration of dipyridamole, in patients undergoing coronary angioplasty with a documented perfusion defect on dipyridamole-thallium-201 scintigraphy. BACKGROUND: Significant flow inhomogeneity is believed to develop during coronary vasodilation induced by dipyridamole, causing a defect in the thallium-201 scintigram. The recently developed intracoronary Doppler guide wire permits assessment of flow velocity variables in normal and stenotic arteries. METHODS: In 17 patients with stable angina we studied changes in time-averaged peak velocity and the diastolic/systolic velocity ratio simultaneously using two 0.014-in. (0.36-mm) Doppler guide wires at baseline and after 4 min of dipyridamole infusion (0.56 mg/kg body weight). Coronary flow velocity reserve and relative flow reserve were correlated with the degree of stenosis on coronary angiography and quantitative analysis of thallium-201 images. RESULTS: No changes in distal flow velocity was observed in the stenotic vessel (5.5 +/- 33.7% [mean +/- SD]), in contrast to a significant increase observed in the adjacent normal vessel (162.4 +/- 39.8%). Poststenotic coronary flow velocity reserve correlated with percent lumen diameter stenosis (r = -0.66, p < 0.05). A correlation was also observed between the relative flow reserve/thallium-201 relative perfusion ratio (r = 0.90, p < 0.001). CONCLUSIONS: To our knowledge, these findings represent the first direct proof of dipyridamole-induced flow inhomogeneity producing a perfusion defect on thallium-201 imaging. The degree of inhomogeneity is related to the extent of the perfusion defect.

Adult↗

PubMed1994

Directional coronary atherectomy can be successfully performed in the elderly.

The influence of age on the clinical and angiographic outcome of directional coronary atherectomy is evaluated. Results demonstrate that DCA can be performed successfully in the vast majority (78.7-90%) of patients in all age groups. However, there is a non-statistical trend toward decreased success rates in the elderly (P > .05). Major ischemic complications and groin complications tend to be more common in the elderly (P > .05). Blood transfusions are required significantly more often in the elderly (P < .05). Directional coronary atherectomy is a useful method of coronary artery revascularization in all age groups, including the elderly.

Aged↗

PubMed1994

Directional coronary atherectomy in women compared with men.

The influence of gender on the procedural outcome of directional coronary atherectomy (DCA) is controversial. This study of 373 consecutive patients (418 lesions) undergoing DCA demonstrates that the procedural success rate of DCA is significantly lower in women compared with men (72.7 vs. 82.9%, p = 0.011). Women have significantly smaller coronary arteries than men (2.5 mm vs. 2.7 mm, p = 0.028) and were older than men (66 vs. 61 years, p = 0.0001). Multivariate analysis identifies small coronary vessel size rather than female gender per se as an independent predictor of poor procedural outcome. Procedural success rates in women with coronary vessel size > or = 2.5 mm is significantly higher (92.2%) than in women with coronary vessel size < 2.5 mm (73.1%), and parallels that in men with vessel size > or = 2.5 mm (89.3%). Inability to engage the ostium of the coronary artery adequately with the guiding catheter and to cross the lesion with the atherectomy device is significantly more common in women compared with men. Major ischemic complication rates are similar in women and men (8.5 vs. 8.7%). Groin complications are significantly more common in women compared with men (13.5 vs. 2.9%). We conclude that procedural success rates in women may be improved by careful patient selection, with particular attention to small vessel size. DCA is best performed in vessels > 2.5 mm in diameter.

Aged↗

PubMed1994

Intracoronary Palmaz-Schatz stent placement after complicated angioplasty: medium term follow-up.

Acute or impending coronary artery occlusion during percutaneous coronary balloon angioplasty represents a serious and potentially life-threatening complication. We studied the clinical and angiographic outcome in 21 patients who underwent emergent intracoronary Palmaz-Schatz stent implantation (11 due to persistent residual stenosis and 10 due to flow-limiting dissection) during complicated balloon angioplasty and who were followed for a mean period of 7.9 +/- 5.7 months. Excluding one patient lost to follow-up, the event-free survival rate was 70%. Six (30%) patients developed adverse clinical events. One died and 3 required elective revascularization procedures. One subacute stent thrombosis was documented. Acute Q-wave myocardial infarction occurred in 2 patients. Among 9 patients studied angiographically 5.6 +/- 2.5 months after stent placement, 2 had developed restenosis (> 50% luminal narrowing). Eleven have remained essentially symptom free. For selected patients, emergent deployment of a Palmaz-Schatz coronary stent, following complicated balloon angioplasty, offers satisfactory long-term results, thus obviating the need for a high risk emergency bypass surgery.

Angioplasty, Balloon, Coronary↗

PubMedDate not supplied

Superior vena caval thrombosis detected by transesophageal echocardiography.

Three patients with clinical suspicion of bacterial endocarditis, induced by either pacemaker or indwelling catheter, underwent transesophageal echocardiography. High short-axis cuts through the great vessels, however, revealed the presence of superior vena caval thrombus in all three patients. Transesophageal echocardiography is more sensitive in establishing the diagnosis of superior vena caval thrombus than surface echocardiography. Comparison of transesophageal echocardiography with other diagnostic modalities is needed in assessing its overall sensitivity and specificity.

Adult↗