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Biomedical subjects

D G Ritter

Publications and source records attributed to D G Ritter.

At least 91 records · Page 5Linked to original sources
PubMed1976

The palliative Mustard operation: rationale and results.

The tendency toward development of severe pulmonary vascular obstructive disease in patients with complete transposition of the great arteries and associated large ventricular septal defect has been well documented. The physiologic consequence of this process is a significant reduction in intercirculatory mixing, resulting in increasingly severe levels of systemic arterial hypoxemia, compensatory polycythemia and an associated significant increase in symptoms. Data indicate that definitive surgical correction in patients with pulmonary arteriolar resistance of more than 10.0 units m2 is associated with a prohibitive operative mortality. However, the "palliative" Mustard operation (that is, intraatrial baffle repair, leaving the ventricular septal defect open) can be accomplished with relatively low risk and substantial hemodynamic benefits to the patient. It is erroneous to assume that the result of the operation will be a mere "reversal" of the preoperative systemic arterial and pulmonary arterial saturations, as shown by a review of the hemodynamic changes attributable to the operation. After the operation, systemic arterial saturations of 80 to 93 percent have been achieved, with a concomitant significant reduction in hemoglobin concentration, to a near normal level in some. Although the long-term prognosis in such patients is unknown, the reduction in symptoms and increase in exercise tolerance soon after operation are most gratifying.

Adolescent↗
PubMed1976

Echo-phonocardiographic and contrast studies in conditions associated with systemic arterial trunk overriding the ventricular septum: truncus arteriosus, tetralogy of Fallot, and pulmonary atresia with ventricular septal defect.

Echocardiography was performed in 62 patients--20 with truncus arteriosus, 14 with tetralogy of Fallot, and 28 with pulmonary atresia with ventricular septal defect. Features common in all three groups were: large single systemic arterial trunk overriding the ventricular septum, mitral-semilunar continuity, large right ventricular dimension, and normal septal motion. Indocyanine green contrast flow patterns were similar and were most helpful in detecting an associated atrial septal defect and in studying the timing and pattern of right-to-left shunting. Echo-phonocardiographic studies revealed that the ejection click coincided with the point of maximal opening of aortic or truncal valve. Left atrial dimension was measured in 55 patients and was normal or small in 41 patients and large in 14 patients. Our observations indicate that left atrial dimension provides a good index of pulmonary flow and can help differentiate those patients with increased pulmonary flow and can help differentiate those patients with increased pulmonary flow (truncus arteriosus) from those patients with reduced pulmonary flow (tetralogy of Fallot and pulmonary atresia with associated ventricular septal defect).

Adolescent↗
PubMed1976

Cor triatriatum: echocardiograhic findings.

The echocardiographic findings in a patient with cor triatriatum are presented. The preoperative echocardiogram demonstrated an unusual structure behind the mitral valve that moved anteriorly during atrial systole. There was also echocardiographic evidence of abnormalities of mitral valve motion, right ventricular and left atrial enlargement, and pulmonary hypertension. Postoperatively, the unusual echo behind the mitral valve had disappeared and the mitral valve appeared more normal. Left atrial and right ventricular dimension had decreased and the pulmonary valve appeared more normal. Fine diastolic mitral valve fluttering, an abnormal echo behind the anterior mitral valve leaflet moving anteriorly with atrial systole, an abnormal pulmonary valve echogram suggesting pulmonary hypertension, and marked right ventricular and left atrial enlargement were the main echocardiographic findings in our patient.

Angiocardiography↗
PubMed1976

Reconstruction of superior vena cava-right atrial continuity and "anatomic" repair of transposition of great arteries with ventricular septal defect.

A superior vena cava-to-right pulmonary artery anastomosis (Glenn procedure), used to palliate certain types of cyanotic congenital heart defects, has usually been left intact at the time of definitive intracardiac repair. Late failure of this shunt has prompted attempts to reestablish superior vena cava-to-right atrium and right ventricle-to-right pulmonary artery continuity. The present patient, a 10-year-old boy with transposition of the great arteries, ventricular septal defect, and mild pulmonic stenosis, had had a Glenn procedure performed at 3 years of age. Angiography demonstrated a patent superior vena cava-to-right pulmonary anastomosis. The appearance of the main left pulmonary artery and of its peripheral branches suggested the presence of pulmonary vascular obstructive disease in the left lung. Therefore, it was considered advisable to reconnect the right ventricle to the right pulmonary artery, which was "protected" by the long-standing low-pressure shunt. The operative result, the intraoperative hemodynamics, and the postoperative assessment of the pulmonary blood flow by means of lung scanning, which clearly demonstrated a preferential perfusion of the right lung, support the validity of this approach.

Arteriovenous Shunt, Surgical↗
PubMed1976

Pulmonary atresia: surgical considerations and results in 103 patients undergoing definitive repair.

Surgical considerations and results of repair of 103 patients with pulmonary atresia are reviewed. The operative mortality was 10%, related primarily to inability to relieve right ventricular hypertension and to low cardiac output after complex repairs involving significant associated anomalies. In a follow-up study ranging from 6 months to 8 years, there were four late deaths, each being a result of persistent right ventricular hypertension. All but one of the surviving patients are in Class I or Class II. Since operative and late mortality and morbidity are related to unrelieved right ventricular hypertension due to restricted pulmonary arterial outflow, it should be possible to improve results by performance of a preliminary systemic-pulmonary arterial shunt for patients with hypoplastic pulmonary arteries and by correction of patients with large systemic-pulmonary arterial shunts before the development of pulmonary vascular obstructive disease. The striking relief of cyanosis, exercise intolerance, and other symptoms, and the generally favorable operative risk, justify the continued application of surgical correction of pulmonary atresia.

Adolescent↗
PubMed1976

Ebstein's malformation. Surgical experience at the Mayo Clinic.

At the Mayo Clinic, 13 patients with Ebstein's malformation have undergone surgical repair since 1963. Their ages ranged from 18 months to 51 years (median 13 years). Ten patients were in Functional Class III or IV. Marked cardiomegaly, cyanosis, paradoxic emboli, and dysrhythmias secondary to Wolff-Parkinson-White syndrome were indications for operation in the remaining 3 patients. A wide range of anatomic variations was encountered. All 5 patients who underwent tricuspid annuloplasty with plication of the atrialized segment of the right ventricle survived operation. Of 5 patients who underwent prosthetic valve replacement, only one survived. Other procedures included atrial septal defect closure alone in one patient, atrial septal defect closure and relief of pulmonary stenosis in one patient, and tricuspid annuloplasty alone in one patient. One patient had concomitant mapping and division of anomalous conduction pathways. Functional classification improved in 8 of 10 operative survivors. There were two late sudden deaths; both patients had had preoperative dysrhythmias. The data suggest that results are improved when the atrialized segment of the right ventricle is dealt with during repair of the tricuspid valve. A combined ventricular plication and tricuspid annuloplasty yielded better early and late results than did valve replacement.

Adolescent↗
PubMed1975

Frank vectorcardiogram in common ventricle: correlation with anatomic findings.

The influence on the Frank vectorcardiogram of anatomic features in common ventricle was analyzed by comparison of Frank vectorcardiograms in 51 patients who had common ventricle with those of 36 patients who had large ventricular septal defect, 14 of whom had levotransposition of the great arteries and 22 of whom had dextrotransposition. Frank vector loops in common ventricle differed from those in ventricular septal defect by the frequent occurrence of clockwise horizontal rotation, most common in patients with type C common ventricle (no outflow chamber). There was a statistically significant difference in the amplitude of early forces between patients with common ventricle and those with large ventricular septal defect. The degree of overlap of vectorcardiographic features between the two groups is sufficiently great that the vectorcardiogram has limited usefulness in establishing the diagnosis of common ventricle in any individual patient.

Diagnosis, Computer-Assisted↗
PubMed1975

Double-outlet right ventricle associated with persistent common atriventricular canal.

A variant of double-outlet right ventricle (DORV) associated with common atrioventricular (A-V) canal was identified. As yet, this syndrome has not been successfully repaired. Of 16 patients with this diagnosis, 14 had the diagnosis confirmed at postmortem examination and two had the diagnosis confirmed by exploratory cardiotomy. The 16 patients were divided into two groups according to the position of the cardiac apex: group 1, ten patients with levocardia, and group 2, six patients with dextrocardia and ventricular inverson. When pulmonary stenosis was present, the clinical presentation was similar to that in tetralogy of Fallot, and when such stenosis was not, the presentation was similar to that in ventricular septal defect with bidirectional shunting. The electrocardiogram had the typical feature of common A-V canal. The right ventricular angiocardiogram had features typical of DORV. The left ventricular angiocardiogram revealed left ventricular outflow deformity typical of A-V canal in patients with levocardia but not in those with dextrocardia. Splenic anomalies were commonly seen (nine of the 16 patients). Asplenia was present in seven, and polysplenia in two. Ten patients had persistent left superior vena cava, seven had common atricum, six had anomalous pulmonary venous connection, and three had subaortic stenosis. Twelve of the 16 patients had pulmonary stenosis. Of the 16, 14 had common A-V canal (Rastelli type C) and two had a ventricular septal defect of the persistent common A-V type.

Adolescent↗
PubMed1975

Fluttering of atrioventricular valves in patients with d-transposition of the great arteries after Mustard operation: an echographic observation.

Postoperative echocardiograms were obtained in conjunction with cardiac catheterization in 14 patients with d-transposition of the great arteries who had undergone the Mustard operation. All 14 patients had atrioventricular valve fluttering demonstrated echographically, although the degree and type of fluttering of both valves varied in each patient. Significant tricuspid valve fluttering was not demonstrated in two patients. Atrioventricular valve fluttering was not related to any one hemodynamic residual. The study suggests that atrioventricular valve fluttering was related to the relatively restrictive atrial tunnel, resulting in turbulent blood flow across these valves. Two patients with d-transposition of the great arteries who underwent repair by the Rastelli operation (without an intra-atrial baffle) did not have atrioventricular valve fluttering.

Adolescent↗
PubMed1975

Echocardiographic contrast studies: initial experience.

Echocardiograms were obtained simultaneously with the standard indocyanine green injections performed during cardiac catheterization. When injected into cardiac chambers, indocyanine green produced a cloud of echoes that enabled us to visualize characteristic flow patterns in the presence of normal and abnormal cardiac hemodynamics. More than 300 echocardiographic contrast studies have been recorded in patients with various congenital and acquired cardiac defects. The patterns obtained were reproducible, sensitive, and specific.

Cardiac Catheterization↗
PubMed1975

Identification of the conduction system in corrected transposition and common ventricle at operation.

The high incidence of surgically induced heart block in patients with levotransposition of the great arteries is now better understood because of recent anatomic demonstration of an unusual anterior location of the atrioventricular specialized conducting tissue. The two cases reported herein proved electrophysiologic confirmation of this previously described anatomy. The specialized conducting bundle was easily and consistently identified and then avoided in successful surgical correction in one patient with common ventricle, type A-3, and in another with corrected transposition, large ventricular septal defect, and valvular pulmonary stenosis. Electrophysiologic identification of the atrioventricular conduction tissue at the time of operation may decrease the incidence of heart block and offers additional optimism for successful correction of levotransposition complexes.

Atrioventricular Node↗
PubMed1975

Echocardiographic features of straddling tricuspid valve.

Echocardiographic features were studied in four patients with straddling tricuspid valve, a rare and complex cardiac anomaly that may defy diagnosis by angiocardiography. The most significant echocardiographic feature was a septal echo recorded at a depth corresponding to the midportion of the tricuspid valve with one of the tricuspid valve leaflets opening posterior to the ventricular septum in diastole. Certain of the features, which appear to be distinctive for this anomaly, have not previously been described.

Adolescent↗