Double-chambered Right Ventricle Research Articles

Double Chambered Right Ventricle in 9 Cats

Background: Double‐chambered right ventricle (DCRV) is a frequently recognized cardiac congenital abnormality in humans. It has been described in dogs and in 1 cat. However systemic description of clinical and echocardiographic features of the disease in cats is currently lacking from the veterinary literature. Animals: Nine cats with DCRV are described. Results: The cats ranged from 4 months to 10 years of age. Eight cats at presentation were asymptomatic and 1 cat had chylothorax. In all cases echocardiography revealed abnormal fibromuscular bundles obstructing the mid‐right ventricle, dividing the chamber into 2 compartments. The proximal right ventricular compartment was markedly hypertrophied, and right atrial dilation was usually present. The mean pressure gradient measured across the stenotic area was 130 ± 50 mm Hg. Concurrent abnormalities included a ventricular septal defect (n = 2); aortic malalignment, aortic insufficiency (n = 1); and congenital peritoneal‐pericardial diaphragmatic hernia (n = 1). Two cats had systolic anterior motion of the mitral valve, one of which had concurrent left ventricular hypertrophy. Five cats have remained asymptomatic for a median period of 3.6 years (range, 3.3–5 years) and 3 cats have developed clinical signs associated with congestive heart failure (at 2, 3.3, and 9 years). One cat showed progressive lethargy and exercise intolerance and underwent partial ventriculectomy at the age of 2 years. This cat died during the operation with electromechanical dissociation. Conclusions: DCRV is a congenital cardiac abnormality that may be more common than previously recognized.

Cardioverter defibrillator implantation in a patient with double chambered right ventricle

Double-chambered right ventricle (DCRV) is a rare form of congenital heart disease in which the right ventricle is divided into a high-pressure inlet site and a low-pressure outlet site by anomalous muscle bands. We describe a patient with DCRV presenting with ventricular tachycardia.

Sustained monomorphic ventricular tachycardia associated with unrepaired double-chambered right ventricle

Double-chambered right ventricle (DCRV) is a congenital anomaly characterized by the division of the ventricular cavity into two chambers separated by an abnormal hypertrophied muscular band or by severe hypertrophy of the muscle wall. Two adult patients with a diagnosis of DCRV presented sustained monomorphic ventricular tachycardia. In both cases, the clinical tachycardia was induced with programmed stimulation. After surgically resecting, the muscular band tachycardia could no longer be induced in the patient who underwent follow-up electrophysiological study. The outcome was favourable; there was no clinical recurrence of ventricular tachycardia in the two patients at 48 and 36 months, respectively.

Types of Obstructions in Double-Chambered Right Ventricle: Mid-Term Results

Background The double-chambered right ventricle (DCRV) is increasingly recognized as a distinct obstruction entity. The nature of the obstruction is not well defined. Methods Patients with DCRV were prospectively studied during the last 4 years according to the following criteria: 1) pressure gradient by echo Doppler and cardiac catheterization within the right ventricle; 2) angiographic demonstration, and 3) surgical confirmation. Results From March 1997 to March 2001, 10 new cases were included. Age ranged from 2 to 14 years (mean 9.5 ± 4.4 years), weight ranged from 9.9 to 75 kg (mean 23 ± 13.6 kg), and height from 0.85 to 1.48 m (mean 114 ± 19 cm). Systolic gradient by echo Doppler ranged from 20 to 135 mmHg (mean 86 ± 44 mmHg) and by cardiac catheterization, 18 to 130 mmHg (mean 78 ± 35 mmHg). In terms of angiographic findings, in six patients the right ventriculogram showed an oblique and low obstruction; in four patients the obstruction was high and horizontal. With regard to surgical findings, angiographic findings were confirmed by the surgeon except in one patient, in whom both types of obstruction were present. No mortality was observed. With follow-up 4 to 40 months after surgery (mean 24 ± 15 months), 8 of 10 patients were evaluated; all corresponded to class I NYHA. Systolic gradient by echo Doppler ranged from 0 to 11 mmHg (mean 4 ± 6 mmHg). Conclusions DCRV is produced by the following three types of muscular obstructions: low and oblique obstruction; high and horizontal obstruction, and mixed obstruction. Mid-term surgical results are satisfactory.

Surgical correction of double-chambered right ventricle in dogs.

Double-chambered right ventricle (DCRV) is possibly an emerging congenital cardiac anomaly in dogs. The defect causes clinical and pathophysiologic signs similar to those of congenital pulmonic stenosis in dogs but has distinct diagnostic features, breed predilections, and implications for treatment. The defect is often associated with clinical signs early in life. Surgical correction of DCRV can be undertaken with the aid of cardiopulmonary bypass and offers the prospect of an improved clinical outcome.

Association of tetralogy of Fallot with a distinct region of del22q11.2

Congenital heart defects (CHDs) appear in greater frequency among relatives of patients and in individuals with DiGeorge syndrome (DGS) or velo-cardio-facial syndrome (VCFS). A majority of these patients and part of the apparently nonsyndromic CHD patients with conotruncal defects manifest hemizygous deletions within chromosome 22q11.2 (del22q11). We tested myocardial tissues of 31 CHD patients, 21 with tetralogy of Fallot (TOF) and 10 with a double-chamber right ventricle (DCRV). DNA isolated from tissues removed at corrective surgery was analyzed for homo- or heterozygosity of nine polymorphic short tandem repeat (STR) markers along the 22q11.2 region. DNA from the blood of 45 healthy individuals represented the general population. Ten of the 21 TOF patients (48%) showed homozygosity for three or more consecutive markers, indicating deletions of various sizes. No such indication was found for DCRV patients. Heterozygosity for markers D22S1648, D22S941, and D22S944 was lower in the TOF group than in normal controls, defining a minimal critical region (MCR) for the deletion. Our findings support an association between TOF and hemizygosity in 22q11.2, suggesting a distinct region, between markers D22S1638 and COMT, that may harbor TOF susceptibility genes.

Clinical, echocardiographic, and angiographic profile of patients with double-chambered right ventricle: experience with 48 cases.

Forty-eight patients with double-chambered right ventricle (DCRV) were prospectively studied over a 3-year period. Clinical, echocardiographic, hemodynamic, and angiographic studies were done in all. Three patients were studied postoperatively also. Fifteen patients underwent surgery confirming the diagnosis. Echocardiography detected anomalous muscle bundles (AMBs) in 39/41 patients in whom this study was carried out. Angiographically AMBs were best demonstrated in anteroposterior views in a systolic frame. Common associated anomalies found with DCRV were ventricular septal defects (69%), pulmonary valve stenosis (38%), and double-outlet right ventricle (10%).

Double chambered right ventricle: delineation by multiplane transoesophageal echocardiography

Three consecutive patients (median age 5 years; median weight 15 kg) with double chambered right ventricle (DCRV) were studied by multiplane transoesophageal echocardiography (TOE), using a specially designed paediatric probe. Using a 30° angulation from the longitudinal plane, the body and outflow tract of the right ventricle could be imaged with minimal foreshortening, allowing detailed description of the level and nature of obstruction. In all cases, angiography and subsequent surgical inspection confirmed the TOE findings. Multiplane TOE should avoid the necessity for angiography in the preoperative assessment of this unusual lesion.

Surgical Repair without Ventriclotomy for Double-chambered Right Ventricle with Ventricular Septal Defect: A Case Report.

A 3-year-old boy with double-chambered right ventricle (DCRV), ventricular septal defect (VSD) and pulmonary stenosis underwent successfully surgical correction without a right ventriculotomy. This surgical approach consisted of a combined right atriotomy and pulmonary arteriotomy. A perimenbranous VSD was closed through the tricuspid valve, and the anomalous muscle bands of right ventricular outflow obstruction were resected through both the tricuspid valve and pulmonary valve. The pressure gradient between the right ventricle and pulmonary artery decreased from 70mmHg to 20mmHg. No major complications occurred after the repair. The transatrial approach with pulmonary arteriotomy is an appropriate and effective method to correct a DCRV.

The diagnosis and surgical treatment of double-chambered right ventricle

Background: Double-chambered right ventricle (DCRV) is a rare congenital anomaly. From January 1990 to February 1993, 60 patients with DCRV were identified among 1,094 patients with congenital defects of the heart who had open-heart surgery in our hospital. Thirty-six patients were males, and 24 were females, with a mean age of 9.3 years (from 3 to 28 years). Various cardiac anomalies were found to be associated with DCRV. The most common was ventricular septal defect (VSD); 52 patients (86.7%) had VSD, and 6 (10%) had other cardiac lesions. Aims: This study summarises our experience in diagnosing DCRV and surgical correction of the anomaly. Methods: Preoperative diagnosis of DCRV depended mainly on 2-dimensional echocardiography, cardiac catheterisation and cineangiography. Surgical correction consisted of resection of anomalous muscle bundles and correction of associated anomalies through a right ventriculotomy. Results: There was 1 hospital death (1.7%); 59 patients survived (98.3%). The pressure gradient of the right ventricle decreased from 49±23 mmHg (mean±SD) preoperatively to 16±6 mmHg postoperatively (p < 0.001). Patients were followed for 0.3 to 3 years (1.8±0.9 years). No major symptoms were documented at follow-up. Conclusion: Excellent results were obtained with surgical correction of DCRV and related anomalies.

Malalignment-type ventricular septal defect in double-chambered right ventricle

Double-chambered right ventricle (DCRV) is commonly associated with ventricular septal defect (VSD). In this study, an assessment was made of the relevance of a malalignment-type VSD to hemodynamic and morphologic features in DCRV. During an 8.5-year period, 53 patients with DCRV were enrolled after study with echocardiography, catheterization, and angiography. Patients were divided into 2 groups: group I included 40 patients, aged 3.7 +/- 3.2 years, with a malalignment-type VSD; group II consisted of 13 patients, aged 8.6 +/- 2.7 years, without a malalignment-type VSD. History of congestive heart failure in infancy was present in 21 group I and 2 group II patients (53% vs 15%, respectively, p <0.05). The mean pulmonary-to-systemic flow ratio was significantly higher in group I than in group II (1.89 +/- 0.74 vs 1.14 +/- 0.21, respectively, p <0.05). The mean pressure gradient across the right ventricular outflow tract was lower in group I than in group II (41 +/- 16 vs, 73 +/- 33 mm Hg, respectively, p <0.05). Among 42 patients who had a series of echocardiograms recorded, progression of pressure gradient was evident in 35: 28 in group I and 7 in group II. A subaortic ridge was present exclusively in 29 group I patients (73%). Prolapse of the aortic valve was present in 26 (49%): 20 group I (50%) and 6 group II (46%) patients. Aneurysm formation of the septal defect was found in 17 (43%) and 7 (54%) group I and II patients, respectively. It can be concluded that a history of congestive heart failure was more common in DCRV patients with a malalignment-type VSD. Malalignment-type VSD is significantly associated with a larger pulmonary-to-systemic flow ratio and subaortic ridge.

Color flow Doppler in the diagnosis of double-chambered right ventricle: a demographic and echocardiographic study.

The purpose of this study was to evaluate the demographic and echocardiographic data of patients diagnosed with double-chambered right ventricle and attempt to explain a perceived rise in the incidence. Double-chambered right ventricle (DCRV) is a division of the right ventricle into two chambers by a hypertrophied muscle bundle. The medical records of patients diagnosed with DCRV were reviewed, and demographic, echocardiographic, and catheterization data were tabulated. Annual incidence of DCRV, based on year of birth, was compared to yearly detection rate, based on year of DCRV diagnosis. To evaluate the influence of color flow Doppler on the frequency of diagnosis of DCRV, demographics of patients born prior to September 1986 (when utilization of color Doppler began in our institution) were compared to those born after that date. Despite an unchanged annual incidence of DCRV, yearly detection rate of this lesion rose significantly following the introduction of color flow Doppler to our institution (September 1986). DCRV was diagnosed earlier and was accompanied by earlier catheterization, which also showed lower right ventricular body gradients after September 1986. Associated anomalies, both cardiac and noncardiac, in our population differed from those reported in previous series. This study infers that the advent of color flow Doppler significantly enhanced the diagnosis of DCRV in our pediatric patients and led to a perceived rise in incidence.

Balloon dilatation of primary infundibular stenosis of the right ventricular outflow tract

Primary infundibular stenosis is an uncommon cause of right ventricular outflow tract obstruction.1-4 Most such cases have an associated ventricular septal defect that is usually smalll; some patients develop infundibular stenosis after spontaneous29 s or surgical closure4 of the ventricular septal defect. Infundibular pulmonic stenosis progresses more rapidly than valvular pulmonic stenosis L s and surgery has been the only treatment.l, 6 Balloon dilatation is the treatment of choice for valvular pulmonic stenosis and has been found useful in palliating the condition in infants and children with obstruction to the right ventricular outflow tract.7-s Welo have recently shown that balloon dilatation is partially effective in reducing the outflow tract gradient in double-chambered right ventricle (DCRV). In this paper we report a patient with infundibular puimonic stenosis in whom balloon dilatation was successful in reducing the outflow tract gradient. A 15-year-old girl presented with a history of dyspnea on exertion of 5 years’ duration that had progressed to class III (New York Heart Association) over the last year. She was in sinus rhythm, without heart failure, and was not cyanotic. Clinically, she had features of severe right ventricular outflow tract obstruction. The electrocardiogram (ECG) showed right axis deviation (110 degrees), right ventricular hypertrophy, and upright T waves in the right precordial leads. There was no poststenotic dilatation of the pulmonary artery in the chest x-ray film. Echocardiography showed hypertrophy of the right ventricle, a large pulmonary artery, a narrowed right ventricular outflow tract, and intact atria1 and ventricular septa. Doppler echocardiography demonstrated a gradient of 77 mm Hg across the right ventricular outflow tract without valvular regurgitation. Cardiac catheterisation (Table I, Fig. 1) showed infundibular stenosis of the right ventricle with a gradient of 80 mm Hg. Angiography confirmed the diagnosis of infundibular pulmonic stenosis with good ventricular systolic function (Fig. 2). The stenosed segment was dilated with the double balloon technique using 20 and 18 mm balloons (Boston Scientific Carp, Mansfield, Mass.) (Fig. 2). A total of five inflations reduced the gradient to 45 mm Hg. She was discharged on a regimen of o-blockers (propranolol, 120 mg/

SURGICAL TREATMENT OF DOUBLE CHAMBERED RIGHT VENTRICLE IN ADULTS

Double chambered right ventricle (DCRV) is common in children, and rarely occurs in adults. Three operated cases of DCRV in a 46-, 46-, and 62-year-old patients are described. The peak systolic pressure gradient in the right ventricle was 110 mmHg in case 1, 80 mmHg in case 2, and 150 mmHg in case 3. A right ventriculotomy in a low pressure chamber was performed in cases 1 and 3, and a longituidinal right ventriculotomy from a low to high pressure chamber was used in case 2 associating with VSD. After surgery, the pressure gradient in the right ventricle disappeared but end-diastolic high pressure was recognized in all patients. It was suggested that deterioration of right ventricular diastolic compliance remains after surgery in adult patients with DCRV.

Pulmonary valve-moderator band distance and association with development of double-chambered right ventricle

Double-chambered right ventricle (DCRV), a form of right ventricular outflow obstruction that sometimes accompanies a ventricular septal defect (VSD), is associated with superior and rightward displacement of the septal insertion of the moderator band. It was hypothesized that this superior displacement is present and identifiable by echocardiography in patients with a VSD even before right ventricular outflow tract obstruction develops. Eight patients who had a previous echocardiographic study showing a VSD alone were echocardiographically diagnosed as having DCRV. Their initial echocardiographic studies were reviewed, and superior displacement of the moderator band was quantified by measuring the distance between the pulmonary valve and moderator band, normalized to tricuspid anulus diameter. These measurements were compared with those from the initial studies of the following 3 other groups: (1) an age-matched group of 10 patients with no structural heart disease; (2) an age-matched group of 10 patients with a VSD who did not develop DCRV; and (3) a group (not age-matched) of 10 patients with VSD and DCRV in whom subpulmonary obstruction was present on the initial study. The 8 patients who eventually developed subpulmonary obstruction had significant superior displacement of the moderator band at the time of their initial echocardiogram compared with that of the 2 age-matched control groups (p < 0.01). In contrast, there was no significant difference in moderator band displacement between these patients and the 10 with DCRV who already had right ventricular outflow obstruction at their initial study (p = not significant). Superior displacement of the moderator band is quantifiable by 2-dimensional echocardiography and may help to predict which infants with a VSD are at risk to develop subpulmonary obstruction.

Double-Chambered Right Ventricle

Thirty (10.8%) of 279 patients undergoing correction of a ventricular septal defect (VSD) from January, 1972, to September, 1986, also had a double-chambered right ventricle (DCRV). Age at operation ranged from 1.3 to 18.8 years (mean, 6.7 ± 4.5 years [± standard deviation]). Seventeen patients were male, and 13 were female. Two-dimensional echocardiography was used after 1978 in the initial evaluation of 20 patients; however, the diagnosis of DCRV was made with the use of subcostal views only since 1984 in 4 of 5 patients. Surgical correction consisted of closure of the VSD and resection of anomalous muscle bundles through a right ventriculotomy (28 patients), and right atriotomy (2 patients). All patients survived and are asymptomatic 4.2 ± 3.4 years following operation. Six patients have undergone catheterization postoperatively and 8 patients had intraoperative pressure recordings. The mean preoperative ratio of right ventricular to left ventricular pressures was 0.67 ± 0.22 compared with 0.34 ± 0.15 postoperatively ( p < .001). In 2 patients, DCRV was not recognized preoperatively or at VSD closure through a right atriotomy, and reoperation was necessary after DCRV was demonstrated at postoperative catheterization. DCRV may occur in approximately 10% of patients undergoing correction of VSD. Careful evaluation of echocardiographic and catheterization data preoperatively and careful evaluation of the anatomy intraoperatively are necessary so that DCRV not be overlooked, especially because most VSDs are now closed through the right atrium. Successful correction of VSD and DCRV is associated with excellent long-term results.

The right ventricular pouch: a proposed explanation for the electro-vectorcardiographic pattern of double chambered right ventricle.

The presence of a specific deformity of the right ventricle in association with the double-chambered right ventricle (DCRV) has been discovered in 8 of 14 individuals undergoing detailed study for DCRV. Investigational study employing multiple angiographic projections with selective angiography has allowed precise morphological identification of this deformity as a contractile pouch located arising from the outflow tract of the right ventricle. Comparison of the angiographic data with the electro-vectorcardiographic findings of DCRV suggests that these highly specific electrical features of DCRV correlate with the position and location of the contractile pouch.

Combined double chambered right ventricle and discrete subaortic stenosis.

Nine cases of combined double-chambered right ventricle (DCRV) and discrete subaortic stenosis (DSAS) are presented. A review of 1077 consecutively catheterized patients indicates an association of these two uncommon anomalies nine times greater than expected. One or both obstructive lesions may be hemodynamically significant and require surgery. Whenever DCRV or DSAS is suspected or identified, the cardiac catheterization should include studies of both the right and left ventricles.

Double-chamber right ventricle: experience with 17 cases

Double-chamber right ventricle (DCRV) is a distinct anatomic entity created by a high take-off of the moderator band resulting in obstruction to flow within the sinus portion of the right ventricle. Frequently associated with a VSD, DCRV exhibits no typical clinical findings, and thus cardiac catheterization and angiography are requisite for its identification. Proper presurgical diagnosis and full knowledge of associated cardiac lesions should provide a minimal operative risk and excellent prognosis for patients with DCRV.