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PubMed1996

Surgical management of complete atrioventricular canal associated with tetralogy of Fallot.

Between 1984 and 1993, 12 children with an atrioventricular canal and tetralogy of Fallot underwent surgical repair. The mean(s.d.) age at operation was 58(18) months, and the mean(s.d.) body weight 15(4) kg. Nine patients underwent 11 palliative procedures. The ventricular septal defect was closed through a combined (right atrial and right ventricular) approach in nine cases, and through a right atrial approach in three, using a prosthetic patch with a wide anterior extension, secured with a running suture. The 'ostium primum' defect was closed with a separate prosthetic patch in 11 cases (double-patch technique). Right ventricular outflow obstruction was relieved by a composite infundibular patch (seven cases) or a transanular patch (five). There were four hospital deaths (33%). These were caused by low cardiac output in three cases and infection in one (three deaths occurred in patients with a transanular patch). One patient has so far died during follow-up. Assessment at 50(36) months by echo-Doppler showed moderate-to-severe 'mitral' regurgitation in three cases, and moderate 'tricuspid' regurgitation with right ventricular dysfunction in one case. Two patients have required further surgery.

Blood Vessel Prosthesis↗
PubMed1994

Result of biventricular repair for double-outlet right ventricle.

The choice of optimal repair for many patients with double-outlet right ventricle continues to challenge the heart surgeon. We present the results of a 10-year surgical experience with the biventricular repair for double-outlet right ventricle with situs solitus and atrioventricular concordance. Preoperative anatomic findings within this population of 73 patients are detailed. These morphologic features are correlated with type of anatomic repair and clinical outcome. Patients were classified by ventricular septal defect location. Normal coronary anatomy was found in the majority of patients with subaortic and doubly-committed ventricular septal defects. Patients with subpulmonary and noncommitted ventricular septal defects had a wide variety of coronary anatomy. Patients with subpulmonary and noncommitted ventricular septal defects also had a considerably higher prevalence of aortic arch obstruction. A tricuspid-to-pulmonary annular distance equal to or greater than the diameter of the aortic annulus was found to indicate the possibility of achieving a conventional ventricular septal defect-to-aorta intraventricular tunnel repair. Tricuspid-to-pulmonary annular distance sufficient for intraventricular tunnel repair predominates in those patients with a right posterior or right side-by-side aorta. Five types of repair were used during the study period: intraventricular tunnel repair, arterial switch with ventricular septal defect-to-pulmonary artery baffle, Rastelli-type extracardiac conduit repair, Damus-Kaye-Stansel repair, and atrial inversion with ventricular septal defect-to-pulmonary artery baffle. Overall actuarial survival estimate at 8 years is 81%. The presence of multiple ventricular septal defects and patient weight lower than the median were nearly significant risk factors for early mortality (p < 0.06). Nineteen patients (26%) required 24 reoperations. Patients with subaortic ventricular septal defects were significantly reoperation free (p < 0.05). Patients with noncommitted ventricular septal defects were at significantly higher risk for reoperation during the study period (p < 0.05). The prevalence of late right or left ventricular outflow obstruction in the nonsubaortic groups is concerning. The median age at repair in this series was 0.76 years, and there was a nonsignificant trend (p = 0.13) for early mortality in patients younger than 1 year of age. These patients tended to have other serious cardiac anomalies associated with double-outlet right ventricle that necessitated early operation. On the basis of these data, we favor early repair for double-outlet right ventricle if possible.

Abnormalities, Multiple↗
PubMed1998

Congenital duplication of the tricuspid valve presenting as a circumscribed obstructive mass in the right ventricular outflow tract.

Congenital duplication of the tricuspid valve is a rare condition. We present a case of a 32-year-old man with an increase in intensity of a long-standing heart murmur and intermittent palpitations. The murmur was evaluated by transthoracic and transesophageal echocardiography that identified a mass in the right ventricle and right ventricular outflow tract resulting in partial obstruction of the right ventricular outflow tract. This mass was determined to be congenital duplication of the tricuspid valve by histologic examination after surgical excision.

Adult↗
PubMed2002

Non-surgical myocardial reduction in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Percutaneous transluminal septal ablation was recently introduced as an alternative to surgical treatment of hypertrophic obstructive cardiomyopathy. In this procedure, alcohol is injected into a proximal septal artery to create a localized myocardial infarction. OBJECTIVES: To characterize the immediate and medium-term results following PTSMA. METHODS: Of 13 patients referred for PTSMA, 8 were found suitable for the procedure. Hemodynamic parameters were evaluated prior to and following the procedure, and clinical and echo-Doppler parameters at 2 weeks and 9 months later. RESULTS: The procedure was technically successful in all patients. Resting left ventricular outflow gradient at rest (by Doppler) fell from 82 +/- 37 to 15 +/- 8 mmHg (P < 0.001) 9 months later. Late post-procedural gradient after the Valsalva maneuver was 2 +/- 24 mmHg. The degree of mitral regurgitation fell from 2.0 +/- 0 to 1.5 +/- 0.5 (P < 0.05). New York Heart Association class for dyspnea improved from 2.8 +/- 0.5 to 1.8 +/- 0.8 (P < 0.01) and Canadian Cardiovascular Society class for angina from 2.0 +/- 1.3 to 1.3 +/- 1.2 (P = 0.08). Complete right bundle branch block developed in six patients, temporary complete atrioventricular block in three, and persistent block requiring permanent pacing in one. No flow in the distal left anterior descending coronary artery (presumably due to spilling of alcohol) was seen in one (with development of a small antero-apical infarction) and ventricular fibrillation 2 hours post-procedure in one. None of the patients died. CONCLUSION: PTSMA provided a substantial reduction in left ventricular outflow gradient associated with an improvement in symptomatology. Serious complications are not uncommon. Long-term follow-up is unknown.

Adult↗
PubMed1984

Late (5 to 132 months) clinical and hemodynamic results after either tricuspid valve replacement or anuloplasty for Ebstein's anomaly of the tricuspid valve.

Late clinical and hemodynamic observations are described in 6 patients who had either tricuspid valve anuloplasty (TVA) (2 patients) or tricuspid valve replacement (TVR) (4 patients) 5 to 132 months earlier for Ebstein's anomaly of the tricuspid valve unassociated with right ventricular outflow obstruction. Of the 6 patients, 4 had improved postoperatively by 1 New York Heart Association functional class and 2 had improved by 2 functional classes. The cardiothoracic ratio decreased 5 to 12 months after either TVR or TVA in all 6 patients (from a mean of 0.72 to 0.62). Repeat cardiac catheterization 5 to 12 months after TVA or TVR disclosed that the right atrial mean pressure had increased from a median of 4.0 to 10.5 mm Hg (p = 0.05); the right ventricular peak systolic pressure had increased from 19.0 to 31.5 mm Hg (p = 0.02); the right ventricular end-diastolic pressure had increased from 5.0 to 9.0 mm Hg (p = 0.05); the systemic arterial peak systolic pressure had increased from 115 to 123 mm Hg (p = 0.03); and the cardiac index had increased (in all 4 patients in whom both pre- and postoperative values were available) from 1.7 to 2.9 liters/min/m2 (p = 0.06). Thus, the tricuspid valve operations in our 6 patients with Ebstein's anomaly were associated with a decrease in symptoms of cardiac dysfunction, a decrease in cardiac size, an increase in cardiac index and an increase in right ventricular and right atrial pressures. The elevation of the right atrial pressures postoperatively may have resulted from increased right ventricular filling pressures, persistent tricuspid regurgitation or bioprosthetic stenosis.

Adolescent↗
PubMed1995

Repair of tetralogy of Fallot in the first six months of life: transatrial versus transventricular approach.

BACKGROUND: This report describes our experience with primary correction of tetralogy of Fallot in infants. METHODS: Fifty-one consecutive infants younger than 6 months underwent primary correction of tetralogy of Fallot between January 1978 and October 1994. Mean age at repair was 4.2 months. Four were neonates. Correction was accomplished through a right ventriculotomy in the first consecutive 22 patients (43%; group A); since 1991, a combined transatrial-transpulmonary approach was used in 29 consecutive patients (57%; group B). A transannular patch was necessary in 33 infants (65%) 16 of group A (73%) and 17 of group B (59%). RESULTS: There was one early death from possible left anterior descending coronary artery distortion in group A and no deaths in group B. Two patients required early reoperation for systemic-to-pulmonary artery collateral ligation (postoperative day 6) and permanent pacemaker implantation (postoperative day 30). There were no late deaths. All 50 survivors are currently asymptomatic and in New York Heart Association class I. Three patients required late reoperations 36 months, 30 months, and 13 months after repair for (1) subaortic stenosis and dysfunctioning dysplastic mitral valve, (2) residual pulmonary artery branch stenosis, and (3) residual right ventricular outflow obstruction. Four patients underwent balloon dilation and stent insertion (1 patient) for peripheral pulmonary artery stenosis 1.5 year to 12 years (mean, 5 years) after initial repair. Actuarial freedom from need for reintervention at 4 years was 78.4% in group A and 85.7% in group B. Two-dimensional and Doppler echocardiographic follow-up studies showed a residual mild to moderate pulmonary artery branch stenosis in 4 patients in group A, and a recurrent subaortic stenosis in 1 patient in group A. Right ventricular peak systolic pressure was less than 40 mm hg in all but 3 asymptomatic patients who had a residual pulmonary artery branch stenosis. Right ventricular end-systolic and end-diastolic volumes showed larger volumes and reduced ejection fraction in group A compared with group B. CONCLUSIONS: This limited experience with repair of tetralogy of Fallot in patients less than 6 months of age demonstrates that the transatrial-transventricular approach is possible in neonates and young infants with a very low mortality and morbidity and also a low incidence of residual lesions. Follow-up echocardiographic data suggest that right ventricular function is better preserved in those patients who underwent the transatrial-transpulmonary repair.

Cardiac Surgical Procedures↗
PubMed1992

Subaortic stenosis caused by an unusual fibrous blood-filled cyst of the left ventricle with outflow tract obstruction associated with a ventricular septal defect.

A large blood-filled cyst formed from a fibrous tissue tag of a right ventricular septal aneurysm was successfully resected. This cyst, which was causing subaortic stenosis, was attached to the margin of the closed ventricular septal defect and not to the mitral valve itself nor the papillary muscle of the left ventricle.

Aortic Stenosis, Subvalvular↗
PubMed1996

Hypertrophic cardiomyopathy in Noonan syndrome.

Noonan syndrome, a well-known multiple congenital anomalies syndrome, is frequently accompanied by cardiovascular diseases including hypertrophic cardiomyopathy (HCM). The incidence of HCM in Noonan syndrome is approximately 20-30% and one-third of cases reveal ventricular outflow obstruction. HCM in Noonan syndrome is occasionally associated with a congenital heart defect, whereas classic HCM seldom accompanies cardiac malformations. Asymmetric septal hypertrophy and symmetric septal hypertrophy (concentric hypertrophy) can be observed both in HCM with Noonan syndrome and in classic HCM, but apical hypertrophy has not been reported in Noonan syndrome yet, although it appears in classic HCM. Congestive heart failure is the major cause of death in patients with HCM in Noonan syndrome, but cases of sudden death have also been reported. The histopathologic findings of ventricular myocardial tissue in HCM with Noonan syndrome are similar to those in classic HCM.

Adolescent↗
PubMedDate not supplied

Supravalvar aortic stenosis: clinical and hemodynamic profile, and surgical outcome.

BACKGROUND: Supravalvar aortic stenosis is the rarest of left ventricular outflow obstructions. Data on this rare entity from India are scarce. METHODS AND RESULTS: We retrospectively analyzed the data of 15 patients (13 males, mean age 15.5+/-10.18 years) with a diagnosis of supravalvar aortic stenosis confirmed by cardiac catheterization. Five patients had morphological features of Williams' syndrome. One patient had diffuse while the rest had discrete type of supravalvar aortic stenosis. Five patients did not have any associated lesions. A 9-year-old male had an ascending aortic aneurysm, and 3 patients had associated peripheral pulmonary artery stenosis. One child had a subaortic ventricular septal defect, and another had severe mitral regurgitation. Twelve patients had electrocardiographic evidence of left ventricular hypertrophy. Three patients had mild aortic valvar stenosis while 2 had aortic regurgitation. Six patients had dilated coronary arteries. Two patients with supravalvar aortic gradients of 20 and 40 mmHg were kept on close follow-up. One patient was not willing to undergo surgery while the other is awaiting surgery. Eleven patients underwent surgical correction. Dacron or pericardial patch aortoplasty was done in all the patients. In addition, one patient each underwent pulmonary artery plasty, ventricular septal defect closure, repair of ascending aortic aneurysm, and mitral valve replacement. The patient with diffuse type of supravalvar aortic stenosis underwent augmentation aortoplasty. Two patients died perioperatively. One was lost to follow-up. Two had moderate residual gradients. The rest of the patients were in New York Heart Association functional class I on follow-up of 6.3+/-4.7 years. CONCLUSIONS: Repair of supravalvar aortic stenosis by single sinus aortoplasty is safe and produces good results.

Aortic Stenosis, Supravalvular↗
PubMed1984

Surgical management of univentricular heart with subaortic obstruction.

In children with a univentricular heart and a rudimentary subaortic chamber, surgical relief of subaortic obstruction caused by a restrictive bulboventricular foramen is associated with high morbidity and mortality. A 6-year-old child with a univentricular heart of the left ventricular type, a rudimentary subaortic chamber, and atresia of the left-sided atrioventricular valve had pulmonary artery banding in infancy. Severe subaortic obstruction subsequently developed. At operation, the pulmonary artery was transected and the stump was anastomosed directly to the posterior aspect of the ascending aorta, diverting left ventricular blood into the aorta through the pulmonary valve. The distal pulmonary artery was anastomosed side-to-side to the ascending aorta to provide pulmonary blood flow. Cardiac catheterization fifteen months after the operation demonstrated an excellent hemodynamic result. When the pulmonary artery is adequate in size, a bypass operation by way of an anastomosis between the ascending aorta and the pulmonary artery is a relatively safe and effective means of relieving the ventricular outflow obstruction caused by a restrictive bulboventricular foramen.

Aortic Valve Stenosis↗
PubMed1990

Differential regulation of right and left ventricular beta-adrenergic receptors in newborn lambs with experimental cyanotic heart disease.

To determine whether chronic hypoxemia secondary to an intracardiac right-to-left shunt alters regulation of the myocardial beta-adrenergic receptor/adenylate cyclase system, we produced chronic hypoxemia in nine newborn lambs by creating right ventricular outflow obstruction and an atrial septal defect. Oxygen saturation was reduced to 65-74% for 2 wk. Eight lambs served as normoxemic controls. beta-receptor density (Bmax) and ligand affinity (KD) were determined with the radio-ligand [125I]iodocyanopindolol and adenylate cyclase activity determined during stimulation with isoproterenol, sodium fluoride (NaF), and forskolin. During chronic hypoxemia, Bmax decreased 45% (hypoxemic, 180.6 +/- 31.5 vs. control, 330.5 +/- 60.1 fmol/mg) in the left ventricle (exposed to hypoxemia alone) but was unchanged in the right ventricle (exposed to hypoxemia and pressure overload). KD was not different from control in either ventricle. Left ventricular isoproterenol-stimulated adenylate cyclase activity was decreased by 39% (30.0 +/- 4.3% increase vs. 44.1 +/- 9.5% increase) whereas right ventricular adenylate cyclase activity was unchanged. Stimulation of adenylate cyclase with NaF or forskolin was not different from control in either ventricle. Circulating epinephrine was increased fourfold whereas circulating and myocardial norepinephrine were unchanged. These data demonstrate a down-regulation of the left ventricular beta-adrenergic receptor/adenylate cyclase system during chronic hypoxemia secondary to an intracardiac right-to-left shunt.

Adenylyl Cyclases↗
PubMed2006

Impact of selective laser ablation of placental anastomoses on the cardiovascular pathology of the recipient twin in severe twin-twin transfusion syndrome.

OBJECTIVES: We investigated the impact of selective laser ablation on the cardiovascular pathology of the recipient twin in twin-twin transfusion syndrome. STUDY DESIGN: Fetal echocardiograms and medical records were reviewed from 22 pregnancies with severe twin-twin transfusion syndrome where echocardiography was performed before and after laser. RESULTS: Before laser, cardiomegaly associated with right and/or left ventricular hypertrophy without ventricular dilatation, was observed in most cases. Right ventricular and left ventricular systolic dysfunction (shortening fraction <28%) was present in 59% and 27%, respectively, and diastolic dysfunction (based on inflow and venous Dopplers) in 73%. Shortly after laser, biventricular systolic function improved significantly and diastolic function tended to improve (50%, P = .06). Functional pulmonary atresia, secondary to right ventricular systolic dysfunction, resolved in 2 of 2 cases at post-laser echocardiography. On serial assessment, diastolic function was normal in 7 of 10, hydrops regressed in 4 of 5, and neither progressive myocardial hypertrophy nor anatomical right ventricular outflow obstruction were found. CONCLUSIONS: Selective laser ablation in severe twin-twin transfusion syndrome acutely improves biventricular systolic function and tends to improve diastolic function in the recipient twin.

Adult↗
PubMed2000

Utility of cardiopulmonary exercise in the assessment of clinical determinants of functional capacity in hypertrophic cardiomyopathy.

The utility of metabolic gas exchange measurements in evaluating the severity and determinants of exercise limitation was studied during upright symptom-limited cardiopulmonary exercise in 135 consecutive patients with hypertrophic cardiomyopathy (HC) and 50 healthy age- and gender-matched volunteers. Peak oxygen consumption (VO(2)) was less than predicted (age, gender, and size) in 99% patients. Peak VO(2) was significantly associated with New York Heart Association functional class; however, there was considerable overlap of peak VO(2) between classes I and III (70 +/- 15%, 56 +/- 15%, 35 +/- 11%, respectively). Patients with abnormal blood pressure responses and patients with chronotropic incompetence during exercise had lower percent-predicted peak VO(2) than patients with normal blood pressure and heart rate responses during exercise (p = 0.0001 and p <0.001, respectively). Percent-predicted peak VO(2) was similar in patients with and without resting left ventricular outflow obstruction. Of those patients with resting gradients, however, there was a strong inverse correlation between the magnitude of the gradient and peak VO(2) (r = 0.5; p <0.001). In conclusion, peak VO(2) is significantly related to New York Heart Association functional class in this group of patients with HC, but peak VO(2) is a superior measure of cardiovascular performance in individual patients. Our peak VO(2) data indicate that mechanical obstruction has an adverse pathophysiologic effect on functional capacity and provide the rationale to support treatments aimed at gradient reduction. Low peak VO(2) characteristics including those with normal or near-normal left ventricular wall thickness suggests that measurement of peak VO(2) may aid in the differential diagnosis between HC and athlete's heart.

Adult↗
PubMed1984

Pulmonary valve agenesis and supravalvular pulmonary stenosis. Report of a case and review of literature.

Pulmonary valve agenesis is a rare malformation, and is usually associated with a ventricular septal defect. Occasionally it may be associated also with right ventricular outflow obstruction. Children with this syndrome usually die early in infancy either of intractable heart failure or of severe respiratory distress. Rare instances of association with peripheral pulmonary stenoses have also been reported. We report the case of a three-year-old girl, asymptomatic except for failure to thrive, with pulmonary valve agenesis and coarctation of the pulmonary artery trunk.

Child, Preschool↗
PubMed1991

Role of intraoperative ultrasound examination in patients undergoing a Fontan-type procedure.

To determine its potential impact on perioperative surgical management intraoperative ultrasound examination (cross sectional imaging, colour flow mapping, pulsed and continuous wave Doppler) was used in 16 consecutive patients undergoing a Fontan-type procedure. Epicardial cross sectional imaging before bypass defined the precise intracardiac morphology in 15 of 16 patients. The preoperative morphological diagnosis was refined in four patients (25%), and this influenced surgical management in two (12%). Epicardial studies after bypass identified seven residual haemodynamic lesions in five patients (three residual intercardiac shunts, one ventricular outflow obstruction, one pulmonary artery obstruction, two mitral valve regurgitation), and led to immediate revision during a second period of bypass in three (18%). In one patient who required early reoperation residual shunting was not detected after bypass by either colour flow mapping or a contrast study. Final intraoperative studies showed a good surgical result in 14 patients (87%). Flow characteristics and flow velocities within the Fontan circulation could be assessed immediately after the patient came off cardiopulmonary bypass by means of combined pulsed wave Doppler and colour flow mapping in 14 of the 16 patients. Cross sectional studies of the left heart after bypass showed no change in ventricular function and allowed monitoring of volume replacement and ventricular filling. Intraoperative ultrasound was a valuable monitoring technique in patients undergoing a Fontan-type procedure. It refined preoperative diagnosis, monitored ventricular function, and identified or excluded residual haemodynamic lesions in most patients.

Adult↗
PubMed2004

The role of echocardiography in diagnosing double chambered right ventricle in adults.

OBJECTIVE: To evaluate the utility of echocardiography in diagnosing double chambered right ventricle (DCRV) in adults. DESIGN: A retrospective study. SETTING: Department of Congenital Heart Diseases and Department of Cardiac Surgery, Institute of Cardiology, Warsaw, Poland. PATIENTS: 32 patients, mean age 32.5 years, 21 female, and 11 male. INTERVENTION: Transthoracic (TTE) and transoesophageal (TOE) echocardiographic examination in patients with suspected DCRV. MAIN OUTCOME MEASURES: Direct inspection during surgical treatment of 28 patients diagnosed as having DCRV as an isolated lesion or associated with other pathologies. RESULTS: Echocardiography allowed the final diagnosis of DCRV in 26 patients (81%) out of 32 studied. TTE was diagnostic in 5 (15.6%) whereas TOE was diagnostic in 21 of 21 studied by this technique. Of 6 patients with negative TTE, DCRV was identified by cardiac catheterisation in 3 and directly during surgery in the remaining 3. Of 26 patients diagnosed by echocardiography, the anomalous muscle bundle was discrete in 20 (77%) and diffuse in 6 (23%). In 23 patients (88%) right ventricular outflow obstruction was localised low in the right ventricle, and in the remaining 3 (11.5%), the obstruction was localised high in the right ventricle. Abnormal bundles localised high were discrete, bundles localised in the lower part of right ventricle were discrete in 17 (74%) and diffuse in the remaining 6 (26%). DCRV was an isolated lesion in only 2 patients (6.2%). In all subjects surgical inspection confirmed echocardiographic data. CONCLUSIONS: Echocardiography was very useful to diagnose DCRV in adults as well as to identify its anatomic type. Comparing two different approaches, TOE better defines the entire scope of pathology, including estimation of the resultant systolic pressure gradient within the right ventricular cavity.

Adolescent↗
PubMed1994

Causes of sudden cardiac death in patients with replacement valves: an autopsy study.

We retrospectively reviewed 52 hearts from patients who had heart valve replacement more than one month prior to death. In 37 cases death was sudden (less than 6 hours after symptoms). These 37 cases were divided as Group I (15 cases, sudden death related to valve prosthesis); and Group II (22 patients, sudden death not related to valve prosthesis). Causes of death in Group I were valve thrombosis (n = 4), embolization of valve thrombi (n = 2), strut fracture (n = 2), anticoagulation-related hemorrhage (n = 2), perivalvular fistula (n = 1) and left ventricular outflow obstruction (n = 1). Causes of death in Group II were presumed arrhythmia in 14, myocardial infarction in six and aortic rupture in two cases. Severe coronary atherosclerosis (> 75% cross-sectional area luminal narrowing) was present in five of 14 cases dying of arrhythmia and in all six cases with myocardial infarction; in the remaining cases, there was marked cardiac hypertrophy (mean weight 728 +/- 177 grams). The mean age (54 +/- 18 vs. 54 +/- 13 years, respectively) was similar in both groups. Seven of 21 deaths after aortic, 6/12 deaths after mitral, 10/25 deaths after mechanical, and 5/11 after porcine valve replacement were secondary to valve complications. The mean left ventricular thickness was 1.7 cm in both groups, the mean left ventricular cavity dimension 2.8 +/- 1.4 cm in Group I vs. 3.5 +/- 1.4 cm in Group II, and the mean heart weight was 550 grams in Group I vs. 734 +/- 211 in Group II (p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Resting and exercise left ventricular function in patients with hypertrophic cardiomyopathy.

Left ventricular ejection fraction (EF) at rest and during exercise was measured in 19 patients with hypertrophic cardiomyopathy (HCM) by means of radionuclide angiography. The results were compared to those in 20 normal subjects. Based on hemodynamic data, patients with HCM were divided into three groups. In group I, no demonstrable left ventricular outflow obstruction, there were five patients; their mean EF increased from 68% +/- 8.9 (+/- SD) at rest to 74% +/- 9.2 during exercise (p less than 0.05). In group II, latent obstruction, there were six patients; their mean EF at rest (75.2% +/- 8.2) and at peak exercise (78.7% +/- 6.7) was not statistically different (p greater than 0.05). Group III, obstruction present at rest, consisted of eight patients; EF at rest (82.6% +/- 8.5) decreased significantly during exercise (75.6% +/- 7.7, p less than 0.01). In normal subjects resting EF was 66.3% +/- 7.6; it increased to 76.4% +/- 7 (p less than 0.001). Exercise duration and heart rate-blood pressure product were lower in groups II and III. Thus there are significant differences in left ventricular systolic function both at rest and during exercise between these three major hemodynamic subgroups. These findings emphasize the importance of such a hemodynamic classification of HCM.

Adult↗