Year : 2014  |  Volume : 17  |  Issue : 3  |  Page : 242--244

A child with a ventricular septal defect associated with left ventricular outflow tract obstruction


Soumendu Pal, Dheeraj Sharma, Sandeep Khandelwal, Manuj Bansal, Sunil K Nanda, Prabhat Dutta 
 Department of Cardiothoracic and Vascular Anaesthesia, Fortis Memorial Research Institute, Gurgaon, Haryana, India

Correspondence Address:
Soumendu Pal
Department of Cardiothoracic and Vascular Anaesthesia, Fortis Memorial Research Institute, Gurgaon, Haryana
India




How to cite this article:
Pal S, Sharma D, Khandelwal S, Bansal M, Nanda SK, Dutta P. A child with a ventricular septal defect associated with left ventricular outflow tract obstruction.Ann Card Anaesth 2014;17:242-244


How to cite this URL:
Pal S, Sharma D, Khandelwal S, Bansal M, Nanda SK, Dutta P. A child with a ventricular septal defect associated with left ventricular outflow tract obstruction. Ann Card Anaesth [serial online] 2014 [cited 2019 Sep 23 ];17:242-244
Available from: http://www.annals.in/text.asp?2014/17/3/242/135886


Full Text

A 4-year-old male child was admitted with the complaints of frequent respiratory tract infection and limited exercise tolerance with easy fatigability. The child was comfortable at rest; heart rate, blood pressure, peripheral oxygen saturation on room air, and respiratory rate were 96/min, 90/56 mmHg, 100%, and 20/min, respectively. A systolic murmur of Grade IV/VI was audible in the left parasternal area. Transthoracic echocardiography (TTE) showed situs solitus, levocardia, a small outlet ventricular septal defect (VSD), asymmetric septal hypertrophy with a septal thickness of 13 mm at end-systole, myxomatous mitral valve (MV) with systolic anterior motion (SAM) of anterior mitral leaflet (AML) and mild mitral regurgitation (MR). The left ventricle (LV) was hypertrophied and showed good systolic function. The shunt across the VSD was left to right. Doppler assessment revealed a severe left ventricular outflow tract (LVOT) obstruction with a peak gradient of 78 mmHg. There was no patent ductus arteriosus or coarctation of aorta.

The child was scheduled for repair of VSD and septal myectomy to relieve the LVOT obstruction. Intra-operative TEE examination in midesophageal LV long-axis view confirmed the diagnosis of VSD and LVOT obstruction [Figure 1] and [Video 1]. Deep trans-gastric long axis view showed turbulence in LVOT, concentric LV hypertrophy and asymmetric septal hypertrophy [Figure 2]. Continuous wave Doppler across LVOT in deep trans-gastric long axis view [Figure 3] showed a typical dagger-shaped, late peaking spectral Doppler confirming dynamic LVOT obstruction with a peak gradient of 51.4 mmHg. TEE also demonstrated a sub-aortic membrane in the LVOT approximately 13 mm below the aortic valve [Figure 4]. In addition, there was associated SAM of AML [Figure 5] and [Video 1]. The LVOT obstruction was considered secondary to the sub-aortic membrane, SAM of AML and asymmetric septal hypertrophy. Intra-operatively, the sub-aortic membrane [Figure 6] was excised and a careful septal myectomy was performed. The child was weaned off cardiopulmonary bypass with dopamine 5 mcg/kg/min, adequate volume status and ventricular pacing. TEE after cardiopulmonary bypass showed no residual VSD, reduced turbulence in the LVOT and mild MR. The septal thickness at end-systole was 7 mm. The SAM of AML persisted which resulted in some turbulence in the LVOT [Figure 7], but the peak LVOT gradient reduced from 51 mmHg to 28 mmHg. The child developed complete heart block on the 4 th post-operative day and underwent permanent pacemaker implantation on the same day, the child was discharged from intensive care unit on 6 th post-operative day.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}{Figure 6}{Figure 7}

[MULTIMEDIA:1]

Congenital LVOT obstruction occurs in 3-10% of individuals with congenital heart diseases. [1 ] The differential diagnosis of LVOT obstruction in children include hypertrophic cardiomyopathy, discrete membranous sub-aortic stenosis, tunnel-type sub-aortic stenosis, posterior deviation of infundibular septum, [2] septal chordal attachments of MV and accessory endocardial tissue attached to the AML which billow into the LVOT. [3] The jet from the narrowed sub-aortic tract damages the aortic cusps and causes regurgitation; this damage may also render the aortic valve prone to infective endocarditis. [4] The discrete membranous sub-aortic stenosis accounts for 8-10% of all cases of LVOT obstruction in children and is frequently associated with a membranous VSD. [5] The abnormal shear stress due to altered flow patterns cause abnormal proliferation of fibrous tissue, resulting in membrane formation. [6]

There is controversy regarding the surgical management of LVOT obstruction secondary to SAM and asymmetric septal hypertrophy. Rayburn et al., advocate surgical myectomy and showed that it reduces turbulence in the LVOT by reshaping and enlarging it. [7] Lupinetti et al. [8] also showed that the recurrence is higher with resection of the membrane alone, when compared with resection along with adjunctive septal myectomy. Considering higher recurrence with SAM alone, we excised the sub-aortic membrane and carefully performed septal myectomy. Post-bypass TEE showed no residual VSD, mild MR, reduced turbulence in the LVOT and reduced septal thickness. The SAM of AML persisted and the peak LVOT gradient decreased from 51 mmHg to 28 mmHg. The residual gradient across the LVOT could be attributed to SAM of the myxomatous MV tissue. However, the patient developed complete heart block and needed permanent pacemaker implantation. In view of modest residual gradient and mild MR, it was decided to treat the residual SAM conservatively.

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