Search PubMed⌕ Search

Biomedical subjects

P Heintzen

Publications and source records attributed to P Heintzen.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Cross your heart].

Explore the source record for details and available documents.

Abbreviations as Topic↗
PubMed1997

Gadopentetate dimeglumine and iodinated contrast media. Hemodynamic side effects after bolus injections in pigs.

RATIONALE AND OBJECTIVES: The use of bolus injections of contrast media containing gadolinium for magnetic resonance imaging and their potential use as x-ray absorbents require the evaluation of possible cardiovascular side effects. The hemodynamic reactions of high doses (0.6 mmol/ kg) of gadopentetate dimeglumine (gadolinium [Gd]-DTPA, Magnevist) were evaluated and compared with the side effects of ionic (diatrizoate: Urografin 76%) and nonionic (iopamidol, Solutrast 370) radiographic contrast media. METHODS: In 18 pigs, pressure and flow of the systemic and pulmonary circulation were monitored after intracardiac bolus injections (2-4 seconds) of dose volumes of 1.2 mL/kg of each contrast agent. RESULTS: All contrast media decreased the aortic pressure transiently (Gd-DTPA and diatrizoate: -25%, iopamidol: -10%; P < 0.01). Pulmonary artery pressure, cardiac output, and stroke volume increased for several minutes. The vascular resistance declined. Diatrizoate induced stronger and longer-lasting side effects (P < 0.01) than Gd-DTPA and iopamidol. CONCLUSIONS: Despite of similar osmolality, Gd-DTPA induced weaker side effects than equivolumetric applications of diatrizoate. Other than osmolality, other factors such as viscosity and chemotoxicity influence the side effects of contrast media.

Animals↗
PubMed1991

[Flexible aortic valve prostheses: long-term functional results with porcine bioprostheses without mechanical commissure stent and aortic homografts].

The long-term performance of two different types of flexible aortic prostheses was evaluated in 10 patients who received a stentless porcine prosthetic valve (group A) and in 18 patients who underwent aortic valve replacement with an aortic homograft (group B). In group A early postoperative angiography (5-16 days post surgery) revealed a mean gradient across the aortic prosthesis of 8 +/- 6 mmHg. Late postoperative Doppler echocardiography (3.2 +/- 0.9 years post surgery) suggested a mean gradient of 6 +/- 3 mmHg with a Doppler derived valve orifice area of 1.8 +/- 0.6 cm2. Color Doppler visualized mild prosthesis regurgitation in two of the 10 patients and two-dimensional imaging showed no significant leaflet calcification. In group B late postoperative Doppler echography (5.2 +/- 1.6 years post surgery) suggested a mean gradient of 11 +/- 14 mmHg with a mean graft orifice area of 1.8 +/- 0.5 cm2. Color Doppler revealed prosthesis regurgitation in 15 patients (severe 1, moderate 2, mild 12) and two-dimensional imaging visualized significant prosthesis leaflet calcification in two patients. The good hemodynamic function of a stentless porcine bioprosthesis which seems to be preserved for at least several years indicates that the use of the flexible aortic xenograft is worthwhile pursuing. The long-term performance of an aortic homograft is relatively poor and may be due to unsolved problems with regard to sterilizing and storing the valves.

Adult↗
PubMed1989

A "semi-supported" porcine xenograft--description and first clinical use.

The anatomy of valsalva's sinus is such that it decreases the mechanical stress on the leaflets of the aortic valve. Artificial stents impair the hemodynamic performance of an aortic bioprosthesis and lead to unphysiological functional stresses and may also shorten their durability. Therefore a semi-supported xenograft was developed which can be attached with an one-suture row in subcoronary position. This facilitates surgery considerably. Moreover, the commissures can be attached directly to the patient's aortic wall. The semi-supported valve was successfully implanted in a 69 years old patient with a combined aortic valve lesion. Postoperative invasive investigations, including angiography and videodensitometry, showed a normal performance of the valve and a normal anatomy of the aortic root.

Aged↗
PubMed1985

Assessment of coronary and aortic anastomoses after anatomic correction of transposition of the great arteries.

Anatomic correction of transposition of the great arteries always entails circumferential anastomoses of the aorta and coronary arteries. Long-term success of this procedure is predicted on adequate growth of these anastomotic sites. To assess the size of these arteries, we performed one or two cardiac catheterization on 25 children from 1 to 53 months (mean 18.8 months) following anatomic correction. Early studies (mean 12 months) were performed in 23 patients and late studies (mean 30 months) in 13 patients. Age at repair ranged from 2 to 168 months (mean 25.5 months) and 15 patients were less than a year of age. Fifteen patients had undergone previous pulmonary artery banding in preparation for anatomic repair. Postoperative catheterizations showed no area of narrowing at the aortic or coronary anastomoses and no kinking of the proximal coronary arteries. Almost all normalized diameters of the aortic root were larger than normal. There were no differences between early and late measurements after anatomic correction. No patient had a pressure gradient across the aortic anastomosis. It is, therefore, concluded that the coronary and aortic anastomoses allow for satisfactory growth even when there has been previous pulmonary artery banding.

Aorta, Thoracic↗
PubMed1983

Catheter evaluation of left ventricular shape and function 1 or more years after anatomic correction of transposition of the great arteries.

Twenty-eight children were reinvestigated by cardiac catheterization and angiography greater than 1 year after anatomic correction of transposition of the great arteries (TGA). Seventeen patients with simple TGA underwent banding of the pulmonary trunk plus or minus systemic to pulmonary artery shunt to prepare the left ventricle for anatomic correction. In addition to TGA, 10 of the remaining 11 patients had a large ventricular septal defect and 1 had an aorticopulmonary window. They required no preparation of the left ventricle. Age at repair ranged from 2 to 120 months (mean 26). Catheterization 12 to 48 months after anatomic repair revealed a left ventricular end-diastolic pressure of 4 to 14 mm Hg (mean 9.5 +/- 2.5 [+/- standard deviation]). Ejection fraction ranged from 52 to 75% (mean 66 +/- 8). Frame-by-frame computer-assisted analysis of left ventricular (LV) contraction and relaxation was performed in 14 patients and compared with normal left ventriculograms. Shape index, derived as 4 pi X cavity area/perimeter2 X 100, was measured in 24 patients and showed a mean index of 89 +/- 3% at end-diastole and 79 +/- 8% at end-systole. A control group had a mean diastolic index of 86 +/- 6% and mean systolic index of 73 +/- 8%. It is concluded that LV shape after anatomic correction tends to be more globular than normal and changes little during systole. LV ejection fraction and end-diastolic pressure are normal.

Adolescent↗
PubMed1982

Supravalvular pulmonary stenosis after anatomic correction of transposition of the great arteries: causes and prevention.

Twenty-two patients who underwent anatomic correction of transposition of the great arteries at the arterial level at the age of 8 weeks to 14 years were reinvestigated 1-4.6 years (mean 2.0 years) after operation. A Dacron tube was used to bridge the gap between the proximal pulmonary route and the distal pulmonary artery in four patients and a tube made of homologous dura mater (2.5 cm in diameter) was used in 18. The nonvalved conduit was placed on the right side of the ascending aorta in nine patients and on the left side in 13. Supravalvular pulmonary stenosis with a gradient of 45-95 mm Hg was found in three patients, all of whom had had the conduit placed on the right side. There was normal growth of the pulmonary artery proximal and distal to the stenotic area. Operation for the relief of the stenosis with insertion of a pericardial patch across the stenosed area was performed in two patients. We conclude that supravalvular pulmonary stenosis after anatomic correction of transposition of the great arteries occurs only when the new pulmonary artery is placed on the right side of the ascending aorta and that the use of a large tube of dura mater appears to allow for rapid growth in early life.

Adolescent↗
PubMed1980

Clinical and hemodynamic results of the two-stage anatomic correction of simple transposition of the great arteries.

Between 1976-1979, 14 patients with simple transposition of the great arteries (TGA), ranging in age from 1 month to 2 1/2 years, underwent two-stage anatomic correction. Twenty patients underwent a first-stage operation, with three early deaths (15%). After the first-stage operation the peak systolic left ventricular pressure rose from 38 +/- 6 mm Hg to 79.6 +/- 11 mm Hg, with no significant change in end-diastolic pressure or ejection fraction. This was associated with a decrease in the actual pulmonary flow but no change in effective pulmonary flow. Between the first and second stages we allowed a 5-week to 9-month interval. There were four early (29%) and no late deaths. Follow-up was 5-37 months. After an initial period of cardiac failure, all patients became asymptomatic and developed normally. Rapid changes in ECG, vectocardiogram and echocardiogram toward normal were observed. Repeat cardiac catheterization was performed in nine patients, 3 weeks to 2 1/2 years after operation. Left ventricular ejection fraction was normal in all. Two who were investigated early had mild mitral regurgitation, five had minimal aortic regurgitation and one had moderate supravalvar pulmonary stenosis. The aortic and coronary anastomoses appeared to grow normally.

Blood Pressure↗
PubMed1975

[Videodensitometric, angiocardiographic and hemodynamic examinations in corrected tetralogy of fallot].

In 38 children with typical tetralogy of Fallot recatheterization was performed 15 days to 410/12 years after correction. Their age ranged from 47/12 to 181/12 years and their weigh? 14;8 TO 54.4 KG. The biplane angiocardiograms were especially evaluated with respect to thcy to decrease from intraoperative to postoperative values. We did not find a parameter, determined during the operation, which can predict with certainty the operative result, found at the time of recatheterization. The peak pressure ration PRV/PLV seems to be most suitable but in an individual case one cannot rely on it. A diastolic murmur was heart postoperatively in 25 children, 9 of whom had a regurgitation index greater than 10%. In all 38 patients an infundibulectomy was performed, which in every case resulted in a disturbance of the contraction pattern (asynergy) of the right ventricular outflow tract. In the area of the ostium infundibuli small aneurysms were demonstrated in 50% of the cases. They were divided according to their angiographic appearance, the type of asynergy and their visibility on the two standard x-ray projections. In 11 children we observed incompletely resected muscle bundles of the infundibulum. Hemodynamically they were insignificant. Residual muscular infundibular stenoses, causing a pressure gradient, were observed in 8 cases. Aortal indentations of varying degree at the site of cannulation for the extracorporal circulation were present in 91%. In 13 patients an outflow tract reconstruction was necessary. In 8 children the patch was clearly identifiable as such. The necessity of recatheterization after correction of tetralogy of Fallot is discussed.

Adolescent↗