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1.
J Thorac Cardiovasc Surg ; 105(4): 580-90, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8468992

ABSTRACT

In an experimental study in pigs, the function of monocuspid and bicuspid patches was compared to improve surgical reconstruction of a hypoplastic pulmonary root. Segments from glutaraldehyde-treated porcine aortic roots served as monocuspid and bicuspid patches. Their leaflets and commissures were marked with radiopaque metal clips. Marker movements were recorded at 100 frames/sec. Quantification of pulmonary insufficiency, right ventricular stroke volume, as well as pressures in the right ventricle, pulmonary artery, and aorta was performed before and after patch plasty. The cyclic motion of the leaflets showed a three-phase pattern in monocuspid and bicuspid patches: (1) a rapid opening motion with a significantly longer distance to be covered in monocuspid patches (7.5 mm in monocuspid versus 4.9 mm in bicuspid patches); (2) a slow closing motion that was significantly greater in monocuspid patches (31.5% of maximal displacement in monocuspid versus 18.2% and 23.8% in bicuspid patches); (3) a similar rapid closure motion in both types of patches. The commissural expansion was less than 6% for monocuspid and bicuspid patches and began 10 to 20 msec before valve opening. Considerable irregularities in the movement of the different leaflet markers, especially in monocuspid patches, indicated leaflet buckling as a result of redundant leaflet tissue. There was a significant pulmonary regurgitant fraction only in monocuspid patches (19% in monocuspid versus 7% in bicuspid patches) that occurred during early diastole. No pressure gradients were observed across either type of patch. In monocuspid patches, a greater leaflet displacement during rapid closure was correlated with an increased pulmonary insufficiency (r = 0.8875). In conclusion, the function of a bicuspid patch is superior to that of a monocuspid patch for repair of a hypoplastic pulmonary root and allows the construction of a competent and stenosis-free valve mechanism.


Subject(s)
Bioprosthesis , Heart Valve Prosthesis/instrumentation , Pulmonary Valve/abnormalities , Pulmonary Valve/surgery , Animals , Heart Function Tests , Hemodynamics , Prosthesis Design , Pulmonary Valve/physiopathology , Swine
2.
J Thorac Cardiovasc Surg ; 103(6): 1068-73, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1597970

ABSTRACT

Conventional biologic and mechanical prostheses have important limitations with regard to their hemodynamic characteristics and long-term durability. We evaluated the hemodynamic function of a stentless porcine aortic prosthesis in 10 patients by invasive pressure measurements and angiography with videodensitometry 8 +/- 4 days after operation, as well as by Doppler echocardiography 35 +/- 15 months after valve replacement. The early postoperative invasive study revealed a mean gradient of 8 +/- 6 mm Hg across the prosthesis, no regurgitation in eight patients, and mild regurgitation, defined as less than 20% regurgitant fraction, in the remaining two patients. The late postoperative Doppler echocardiographic study revealed a mean gradient across the aortic prosthesis of 6 +/- 3 mm Hg, mean Doppler-derived valve orifice area of 1.8 +/- 0.6 cm2, and color Doppler flow velocity mapping suggested no regurgitation in eight patients and mild regurgitation in two patients corresponding to early postoperative angiography. None of the 10 patients received anticoagulation therapy. The clinical course of all patients was without incident. This stentless aortic bioprosthesis may offer hemodynamic advantage; however, further studies are needed to allow comparison with conventional mechanical and biologic prostheses.


Subject(s)
Bioprosthesis , Heart Valve Prosthesis , Adult , Aged , Aortic Valve/diagnostic imaging , Bioprosthesis/statistics & numerical data , Cardiac Catheterization , Evaluation Studies as Topic , Female , Follow-Up Studies , Heart Valve Prosthesis/statistics & numerical data , Heart Ventricles/diagnostic imaging , Hemodynamics , Humans , Male , Middle Aged , Prosthesis Design , Radiography , Stents , Ultrasonography
3.
Int J Card Imaging ; 7(2): 113-24, 1991.
Article in English | MEDLINE | ID: mdl-1795123

ABSTRACT

Videodensitometry allows to obtain both left and right ventricular ejection fraction (EF) and aortic or pulmonary regurgitant fraction (RGF) from the wash-out curve of contrast medium. We developed this technique to digital densitometry and integrated it in the standard digital image acquisition system 'Digitron' using Siemens user's library. Sources of error like scatter radiation, veiling glare, accumulation of iodine in tissue, and inhomogeneous contrast mixing were considered by using ECG gated image subtraction, background reference regions, data fit to ideal wash-out curves and calculation of EF and RGF exclusively from density differences. The method was validated by phantom studies in which simulated angiocardiograms were generated with given values of EF (50 to 70%) and RGF (0 to 45%). The results tended to overestimate RGF by up to 10 percent points, when image contrast was high and the ventricle was masked poorly by the lead shutters. In the clinical setting, the reliability of the results can be judged from the fit of the wash-out curve presented automatically on the screen on a semi-logarithmic scale. The technique is available to the physician in the catheterization laboratory on-line during or immediately after the examination, which facilitates routine use.


Subject(s)
Absorptiometry, Photon/methods , Stroke Volume , Ventricular Function , Aortic Valve Insufficiency/diagnostic imaging , Aortic Valve Insufficiency/physiopathology , Coronary Angiography , Humans , Pulmonary Valve Insufficiency/diagnostic imaging , Pulmonary Valve Insufficiency/physiopathology
11.
Eur J Cardiothorac Surg ; 2(5): 318-23, 1988.
Article in English | MEDLINE | ID: mdl-3272237

ABSTRACT

For a continued assessment of the two-stage anatomic correction, we have evaluated the postoperative results in terms of clinical status, ECG, ventricular function, aortic root size and stiffness for up to 9 years in all 18 survivors. Weight and height were normal, the ECG was normal except for complete (n = 3) and incomplete (n = 11) right bundle branch block and supraventricular tachyarrhythmias post Blalock-Hanlon septectomy (n = 1) and p-wave abnormalities (n = 6). The pressures and ejection fraction of the left and right ventricles were within normal limits. The end-diastolic and endsystolic left ventricular volume and the muscle volume index were elevated. Six of 17 patients were outside the normal range of the left ventricular ejection fraction-endsystolic stress relationship. The diameter of the aortic root was larger than normal in all patients. There was a relation between the size of the patients at banding and the stiffness of the aortic root after anatomic correction. Patients with simple transposition of the great arteries up to 9 years after anatomic correction develop normally without atrio-ventricular conduction delay, arrhythmias or signs of coronary and myocardial insufficiency. The stiff and enlarged aortic roots do not seem to dilate. The reasons for the elevated left ventricular volumes and muscle volume indices are not clear at present. Primary anatomic correction may prevent these abnormalities.


Subject(s)
Transposition of Great Vessels/surgery , Aorta/physiology , Bundle-Branch Block/physiopathology , Child, Preschool , Cineangiography , Elasticity , Electrocardiography , Follow-Up Studies , Humans , Infant , Infant, Newborn , Pressure , Stroke Volume , Transposition of Great Vessels/physiopathology
12.
Cardiovasc Intervent Radiol ; 11(1): 5-9, 1988.
Article in English | MEDLINE | ID: mdl-3131000

ABSTRACT

To assess the feasibility of quantitative central venous digital angiocardiography, right ventricular spatial orientation, size, and shape were compared with measurements based on conventional angiocardiography, both obtained during routine cardiac catheterization in 21 children with various congenital heart defects. Without systematic error, correlations for end-diastolic and end-systolic volumes were excellent, at r = 0.986 and 0.969, respectively. Ejection fractions were similarly closely correlated. Premature ventricular contractions were common in conventional angiocardiography and absent in digital and angiocardiography. The amount of contrast medium was 36% of that used for conventional angiocardiography. Digital angiocardiography using reduced amounts of contrast medium given through a central venous catheter allows accurate assessment of right ventricular size and function.


Subject(s)
Heart Defects, Congenital/diagnostic imaging , Heart Ventricles/diagnostic imaging , Radiographic Image Enhancement , Adolescent , Child , Child, Preschool , Heart Defects, Congenital/physiopathology , Heart Ventricles/physiopathology , Humans , Infant
13.
Eur Heart J ; 8(3): 313-5, 1987 Mar.
Article in English | MEDLINE | ID: mdl-3582389

ABSTRACT

A 17-year old boy with hypertrophic obstructive cardiomyopathy (HOCM) developed repeated short runs of self terminating ventricular tachycardia 12 hours after starting oral verapamil, which was substituted for propranolol therapy. It is suggested that alterations in sympathetic tone induced by changing from a beta-blocker to a calcium antagonist might have increased myocardial irritability thus favouring genesis of severe ventricular arrhythmias. Verapamil is often considered to be more effective than propranolol in the treatment of HOCM. However, if propranolol is replaced by verapamil one has to take account of the possibility of serious arrhythmias as demonstrated by our case.


Subject(s)
Cardiomyopathy, Hypertrophic/drug therapy , Tachycardia/chemically induced , Verapamil/adverse effects , Adolescent , Humans , Male , Verapamil/therapeutic use
14.
J Cardiovasc Pharmacol ; 10 Suppl 6: S62-70, 1987.
Article in English | MEDLINE | ID: mdl-2485031

ABSTRACT

To gain information on physiologic postnatal cardiac growth in humans and to characterize the left ventricle (LV) when subjected to various types of overload during that period, angiocardiographic volume parameters in infants, children, and adolescents were analyzed. In normal subjects, the relationships between end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) of the LV and right ventricle (RV), as well as the muscle volume (MV) of the LV and body surface area (BSA) were best fit by power functions with exponents of between 1.2 and 1.3. The EDV and ESV of the LV were smaller than those of the RV. Ejection Fraction (EF), muscle volume index (MVI = MV/EDV), and cardiac index (CI) were constant. In pressure loaded LVs, the MVI was elevated, and increased with increasing pressure load. The ESV tended to be smaller and EF tended to be higher than normal. There was no correlation between EF and EDV. In volume loaded LVs, MV was increased; the MVI, as well as the EF, was normal. The EDV and ESV were elevated without correlation between EF and EDV. In complete transposition of the great arteries. MVI diminished, increasing within months as a response to pressure underloading and overloading. In all groups, there was a negative correlation between EF and ESV, as well as between EF and the shape parameter elongation in systole. During postnatal growth, the normal heart grows overproportionally with respect to BSA, with the LV ejecting the same SV as the RV at a higher EDV and ESV. EF, MVI, and CI are age-independent parameters for assessment of cardiac function.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Cardiomegaly/physiopathology , Heart/growth & development , Adult , Child , Child, Preschool , Humans , Reference Standards
15.
Monatsschr Kinderheilkd ; 134(12): 881-3, 1986 Dec.
Article in German | MEDLINE | ID: mdl-3547094

ABSTRACT

In female adolescents with pulmonary embolism such as in the presented 19 year old patient oral contraceptives have to be considered as an etiologic factor. It is important to consider this diagnosis even in that age group. The diagnosis can be verified by intravenous digital subtraction angiography.


Subject(s)
Angiography , Pulmonary Embolism/diagnostic imaging , Subtraction Technique , Adult , Contraceptives, Oral/adverse effects , Diagnosis, Differential , Female , Humans , Pulmonary Embolism/chemically induced , Recurrence
16.
Circulation ; 74(3 Pt 2): I47-52, 1986 Sep.
Article in English | MEDLINE | ID: mdl-3742774

ABSTRACT

In 16 patients, constituting 100% of children followed for up to 7 years after two-stage anatomic correction of complete transposition of the great arteries, clinical and electrocardiographic data, as well as cardiac catheterization data in 12 patients, were analyzed. None of them has had signs or symptoms of coronary or myocardial insufficiency after an adaptation phase of 6 months after anatomic correction. Body weight normalized 3 to 6 months after anatomic correction, and was normal in most cases after 1 year. No atrioventricular conduction delays or arrhythmias definitely attributable to anatomic correction were observed. Peak systolic pressure in the right ventricle was slightly elevated in 10 of 12 patients studied due to residual pulmonary stenosis from the band site. End-diastolic and end-systolic volumes as well as ejection fraction and end-diastolic pressure of the right ventricle were normal. End-diastolic and end-systolic volumes of the left ventricle were elevated (p less than .01), while muscle volume, ejection fraction, and end-diastolic pressure were normal. The pulmonary root was distended during the banding stage and did not dilate as did the aortic root after anatomic correction. Patients with complete transposition of the great arteries up to 7 years after anatomic correction develop normally without atrioventricular conduction delays, arrhythmias, or signs of coronary and myocardial insufficiency. The enlarged aortic root does not seem to dilate. The reasons for elevated left ventricular volumes are not clear at the present time. Earlier operation may prevent these changes.


Subject(s)
Transposition of Great Vessels/surgery , Body Weight , Cardiac Catheterization , Child , Child, Preschool , Electrocardiography , Follow-Up Studies , Humans , Infant , Methods , Stroke Volume , Time Factors , Transposition of Great Vessels/physiopathology
17.
Thorac Cardiovasc Surg ; 34(1): 22-4, 1986 Feb.
Article in English | MEDLINE | ID: mdl-2421442

ABSTRACT

To assess postoperative arrhythmias and AV-conduction defects associated with anatomic correction of simple transposition of the great arteries, 207 standard 12-lead surface and 43 24-hour electrocardiograms of all 17 patients followed after anatomic correction for up to 6.5 years were reviewed. No dysrhythmias or AV-conduction delays definitely attributable to anatomic correction were observed. One patient with a severe complex supraventricular tachyarrhythmia after a Blalock-Hanlon procedure has improved markedly, exhibiting respiratory AV-dissociation and 5 premature atrial complexes/minute 5 years after anatomic correction.


Subject(s)
Arrhythmias, Cardiac/etiology , Heart Block/etiology , Transposition of Great Vessels/surgery , Atrioventricular Node/physiopathology , Bundle-Branch Block/etiology , Child, Preschool , Electrocardiography , Heart Ventricles/physiopathology , Humans , Infant , Postoperative Complications
18.
Am J Cardiol ; 56(8): 514-9, 1985 Sep 15.
Article in English | MEDLINE | ID: mdl-4036837

ABSTRACT

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great arteries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = 11), and compared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 +/- 10) and between 13 and 47 months (mean 24 +/- 10), respectively. The interval between anatomic correction and the investigation ranged from 10 to 29 months (mean 20 +/- 7). After banding, LV ejection fraction decreased (p less than 0.01) and LV peak systolic pressure (p less than 0.01) as well as LV end-diastolic pressure (p less than 0.05) increased. After anatomic correction, these variables and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 patients after anatomic correction was within control range. The highest values were found in the youngest patients at banding and at anatomic correction. In contrast to measures of global myocardial function, such as LV ejection fraction and LV end-diastolic pressure data, the LV end-systolic stress-ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.


Subject(s)
Heart/physiology , Transposition of Great Vessels/surgery , Age Factors , Angiocardiography , Cardiac Output , Child, Preschool , Female , Hemodynamics , Humans , Infant , Male , Systole , Ventricular Function
19.
Eur Heart J ; 6(8): 706-9, 1985 Aug.
Article in English | MEDLINE | ID: mdl-4054141

ABSTRACT

The purpose of this study was the analysis of natural history and right ventricular function of infants and children with valvular pulmonary stenosis. Available for assessment were the pressures in the right ventricle and pulmonary artery in 5 infants and 13 children obtained at two cardiac catheterizations, performed at intervals of 2 to 12 years (mean: 6.5 years) apart, as well as quantitative angiocardiographic data in another group of 38 children. There was no change in the pressure gradient between the right ventricle and pulmonary artery (PG) between the two catheterizations for those with an initial PG of less than 50 mmHg; but a mean increase of 8.6 mmHg year-1 occurred in those with an initial PG of more than 50 mmHg. There were good correlations between increase of PG and the first (r = 0.704) and the second (r = 0.904) catheterizations. End diastolic and stroke volume were normal while end-systolic volume was smaller (P less than 0.01) and ejection fraction greater (P less than 0.01) than normal. The natural history of children with a PG of more than 50 mmHg seems to be different from that with a PG of less than 50 mmHg. In the former group the increase of PG is rapid while PG in the latter does not change over many years. Right ventricular function is usually not impaired in patients with moderate and severe valvular pulmonary stenosis in the pediatric age group.


Subject(s)
Pulmonary Valve Stenosis/physiopathology , Angiocardiography , Blood Pressure , Child, Preschool , Humans , Infant , Infant, Newborn , Pulmonary Valve Stenosis/diagnostic imaging , Stroke Volume , Systole
20.
Radiologe ; 25(8): 381-6, 1985 Aug.
Article in German | MEDLINE | ID: mdl-4059540

ABSTRACT

New techniques of digital image processing have been experimentally tested for the assessment of renal blood flow. The underlying principle in functional angiography is the extraction of flow parameters. Basically, density-time variations of the contrast medium are analyzed from each picture element of a 256 X 256 matrix. The real-time acquisition rate of images was 25/sec. For the calculation of angiographic flow a PDP 11/40 computer was used to interactively perform a time dependent segmentation of the renal arteries and the aorta. Subsequently, volume flow was calculated in relative units for the specific vascular segments under study. 15 control angiograms were made in 5 animals with cardiac output ranging between 0.8 to 2.2 l/min. Unilateral renal blood flow was calculated as 24 +/- 3.4% of pre-renal aortic flow without systematic side differences. Reproducibility from repeated flow measurements showed an SD of +/- 1.8% of the individual pre-renal aortic flow. Renal flow was also measured in 3 animals with an experimentally created 50% flow reduction of the left kidney. Angiographic flow in the left renal artery dropped to 12 +/- 2% of pre-renal flow. The present experimental data suggest that digital angiography has sufficient diagnostic capabilities for the detection of abnormal renal blood flow. The technique may serve as a useful diagnostic adjunct to conventional angiography and has the potential of assisting in the evaluation of renal vascular hypertension.


Subject(s)
Angiography/methods , Renal Circulation , Animals , Swine
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