Studies on cor pulmonale in cystic fibrosis: I. Effects of diuresis.

The effects of acute diuresis in patients with cor pulmonale secondary to cystic fibrosis were studied. Both hemodynamic parameters and arterial blood gas changes were investigated. The major effect noted was a significant reduction of systemic venous pressure. Pulmonary artery and pulmonary artery wedge pressure either remained constant or declined slightly. No consistent changes were noted in cardiac output or arterial blood gases. Acute diuresis of moderate degree appears to be a safe and effective manner in which to treat the systemic venous congestion of cor pulmonale in this situation.

Surgical treatment of interrupted aortic arch in infancy with expanded polytetrafluoroethylene grafts: two-year follow-up results.

The interrupted aortic arch complex is an uncommon but highly lethal combination of anomalies. Multiple approaches have been proposed for the surgical treatment of this complex. These include palliative procedures, direct anastomosis of the interrupted segments, interposition grafting with biological or synthetic conduits, and total correction by closure of the atrial and ventricular septal defects with anastomosis of the proximal and distal aortic segments. This communication reports the good clinical results, noted after 2 years of follow-up, in two consecutive patients with type B interrupted aortic arch who underwent operative repair of the interrupted arch with expanded polytetrafluoroethylene (PTFE) grafts and palliative pulmonary artery banding.

Comparison of exercise and catheterization results following total surgical correction of tetralogy of Fallot.

Although surgery may correct the hemodynamic abnormalities of tetralogy of Fallot (TOF), the long-term effects on exercise tolerance are uncertain. Twenty-eight patients, aged 7 to 30 years, had cardiac catheterization and maximal graded exercise testing to evaluate the adequacy of the ehmodynamic repair and its relation to exercise performance. Patients were tested 2 to 9 years after operation, and 13 previously had had palliative shunt procedures. At catheterization, 23 of the 28 patients had good surgical results. Despite the satisfactory hemodynamics, maximal working capcity (MWC), maximum heart rate, and exercise blood pressure were diminished when compared to normal values. In 10 patients who had exercise studies at catheterization, right ventricular systolic pressure (RVSP) and residual gradients were magnified by exercise. Abnormalities were independent of age at time of correction, time elapsed since surgery, use of patch in the outflow tract, or any antecedent procedures.

Resolution of surgically induced right bundle-branch block.

In a retrospective study, the serial electrocardiograms of all patients with surgically induced right bundle-branch block (RBBB) were reviewed. None of these patients had had RBBB prior to operation. Seven patients who had RBBB from 6 to 16 days after operation showed resolution in ECGs done 3 to 8 months later. Two patients are reported, with documentation by vectorcardiogram, in whom RBBB resolved by 3 and 12 years after operation. The origin of transient forms of RBBB may be different from the long-standing form. If RBBB of long duration is due to operative injury to the proximal right bundle, Purkinje fiber network, or distal branch or branches of the right bundle, or to combinations of these tracts, one may speculate about the possibility of regeneration of the right ventricular conduction system. Since no data are available concerning the long-term prognosis of RBBB and since a progressive conduction disturbance can occur, the resolution of RBBB after many years might carry a better prognosis than its persistence.

Hepatic dysfunction and cardiovascular abnormalities. Occurrence in infants, children, and young adults.

In infants and children, the effect of heart failure and/or cyanotic heart disease on the liver has not been well documented, nor has there been any comparison between the degree of liver dysfunction and hemodynamic factors. Sixty-five patients with cardiovascular abnormalities were examined. Hepatic function, as indicated by laboratory data and histologic liver studies, was compared with the following categories of cardiovascular dysfunction: hypoxemia, systemic venous congestion, and low cardiac output. If any one of these factors was present, or any combination, abnormalities of liver function were usually noted. Patients with both hypoxemia and systemic venous congestion had marked hepatic dysfunction. Those with low cardiac output had the most severe abnormalities. Serial studies indicated that liver function correlated with cardiac status.

Quantification of the Frank and McFee-Parungao orthogonal electrocardiogram in valvular pulmonic stenosis. Correlations with hemodynamic measurement.

In 66 patients with congenital valvular pulmonic stenosis and intact ventricular septum, correlations were obtined among various multiple hemodynamic and orthogonal vectorcardiographic parameters. The Frank and McFee-parungao lead systems were used. The most important hemodynamic parameter evaluated was right ventricular pressure (RVP). RVP correlated best with X terminal to the right (XTR) in both Frank (R = 0.68) and McFee (R = 0.61) systems. The correlation between RVP and Z anterior was poor. The direction of the initial QRS vector on the X axis was helpful in predicting severity. With X initial to the right, especially in McFee, the RVP is most likely to be systemic or less, while with X initial to the left, the RVP is frequently but not necessarily suprasystemic. T vector spatial orientation is not helpful in the assessment of severity.

Intracardiac pressure-sound correlates of echographic aortic valve closure.

Echographic aortic valve closure was compared to the dicrotic notch of the aortic pressure and intracardiac A2 to define the exact temporal relationship of the echographic, pressure, and sound parameters of aortic valve closure. Sixteen children, ages 3--20 years, were evaluated by simultaneous aortic valve echograms, micromanometric aortic root pressure tracings, and intracardiac phonocardiograms recorded at paper speeds of 200 mm/sec. Our observations demonstrated that echographic coaptation of the aortic valve leaflets coincides with the trough of the aortic pressure incisura and the onset of A2. The data suggest that A2 is a result of valve closure.

Right ventricular growth in a case of pulmonic stenosis with intact ventricular septum and hypoplastic right ventricle.

Adequate growth of the hypoplastic right ventricle in a patient with severe pulmonary stenosis with an intact ventricular septum was documented after pulmonary valvotomy in infancy. It is postulated that the growth of the ventricular chamber is largely the result of pulmonary regurgitation resulting from successful pulmonary valvotomy. Based on this and the observations of others on the growth of the hypoplastic right ventricle in pulmonary atresia (with intact septum) cases, an organized approach to eventual total surgical correction is recommended.

Reduced lung volume associated with acquired pulmonary artery obstruction in children.

The effect of postnatal pulmonary artery obstruction on lung growth has not previously been reported. This report describes two patients in whom pulmonary artery banding in early infancy was complicated by complete occlusion of the right pulmonary arter. In each case, the right lung became less voluminous than the left. In one patient, the alevoli of the affected lung were found to be smaller than normal at autopsy. In the other patient, surgical reconstitution of pulmonary arterial flow resulted in a return to normal volume of the affected lung. Observations suggest that pulmonary arterial flow should be restored as early as possible to minimize impairment of lung growth and to avoid irreversible pulmonary hypertension in the opposite lung.

Assessment of the pulmonary vascular bed by echocardiographic right ventricular systolic time intervals.

Echocardiography was used to measure right ventricular systolic time intervals (RVSTI) in 85 normal children (group I) and in 229 patients undergoing cardiac catheterization (group II). Corrected right ventricular pre-ejection period (RPEPC) and right ventricular ejection time (RVETc) (based on regression analysis of group I) and RPEP/RVET were each correlated with pulmonary artery (PA) diastolic and mean pressures and pulmonary vascular resistance (PVR). The best correlation (0.83) was between a second degree polynomial of the RPEP/RVET and PA diastolic pressure. The RPEP/RVET allowed prediction of PA diastolic pressure within 10 mm Hg in 85% of the patients. The utility of RPEP/RVET was confirmed in sequential data of 22 patients, in whom alteration in RPEP/RVET accurately reflected the changing PA diastolic pressure. The RPEP/RVET could not be used to assess PA pressure in six patients with congestive cardiomyopathy nor in 18 patients with complete right bundle branch block (CRBBB).

Ventricular septal defect in infancy: a combined vectorgraphic and echocardiographic study.

Echocardiograms (echo) and vectorcardiograms (VCG) from 40 infants with ventricular septal defects (VSD) were compared with cardiac catheterization data to assess noninvasively the hemodynamics of VSD. The specific aim was to use VCG parameters of right ventricular hypertrophy and echo parameters which reflect pulmonary artery pressure to identify all patients with a nonrestrictive VSD. The configuration of the QRS vector in the horizontal plane was more reliable than individual voltages in assessing right ventricular systolic pressure. Among patients older than 2 months with a clockwise or anterior two-main-vector horizontal loop, 73% (eight of 11) had a nonrestrictive VSD. However, a counterclockwise or posterior two-main-vector loop was also frequently found (43%, six of 14) in infants with a nonrestrictive VSD. The most useful echo parameter was the ratio of right ventricular preejection period-to-right ventricular ejection time (RPEP/RVET), which closely (r = 0.74) reflected the pulmonary artery diastolic pressure. An elevated RPEP/RVET to greater than 0.30 was always associated with a nonrestrictive VSD, although many patients (36%, five of 14) with a nonrestrictive VSD had a normal ratio. By combining both echo and VCG parameters, a nonrestrictive VSD was correctly identified in all patients, while a restrictive VSD was correctly identified in 81% (21 of 26).

Cardiac rhythm after the Mustard operation for complete transposition of the great arteries.

The Mustard operation corrects the effects of congenital transposition of the great arteries by creating an intraarterial baffle to direct pulmonary venous blood to the tricuspid orifice and systemic venous blood to the mitral orifice. To identify the long-term effects of this procedure, we followed 372 patients with complete transposition of the great arteries who survived the Mustard operation for at least three months. The mean follow-up period was 4.5 years (range, 0.4 to 15.9); the mean age at operation was 2.0 years. Mean resting heart rates were consistently lower than those for age-matched normal children. Seventy-six per cent of the patients had sinus rhythm during the year of operation--a figure that decreased to 57 per cent by the end of the eighth postoperative year. Twenty-five patients died during the follow-up period, nine suddenly. Life-table analysis revealed a cumulative survival rate of 91 per cent for 11 years and 71 per cent for 15 years after the operation. No strong risk factor for sudden unexpected death identified. This study demonstrates that extended survival among patients with transposition can be expected after the Mustard operation. However, over time there is a decreasing prevalence of normal sinus rhythm in survivors, as well as a small risk of sudden death.

Heart failure in cystic fibrosis. Treatment and prognosis of cor pulmonale with failure of the right side of the heart.

Failure of the right side of the heart with cardiac dilation and fluid retention occurred in 55 of 170 patients who died of cystic fibrosis; six patients survive. All had severe hypoxia, but 24% had normal PaCO2. Cardiac catheterization showed high mean pulmonary artery pressure and resistance. Pulmonary artery wedge pressure was greater than 12 mm Hg in 40% of the patients. Mean survival was eight months. Male survival was significantly better than female survival. Digitalis treatment was of no clear benefit. Tolazoline hydrochloride was also ineffective. Recent medical advances have not substantially affected prognosis.