**4.1.4.1 Chest x-ray**

In most cases, the chest film shows no cardiomegaly, but a characteristically dilated main pulmonary artery segment (post-stenotic dilatation) is visualized. The magnitude of pulmonary artery dilatation has no bearing on the severity of pulmonary valve stenosis.

#### **4.1.4.2 Electrocardiogram (ECG)**

The ECG shows right ventricular hypertrophy; the degree of right ventricular hypertrophy is proportional to the severity of stenosis. Right atrial enlargement may be present.

#### **4.1.4.3 Echocardiogram**

The echo may show right ventricular enlargement without paradoxical septal motion and thickened and domed pulmonary valve leaflets. The Doppler flow velocity across the site of obstruction is increased and the magnitude of this increase reflects the severity of

Fig. 1. Auscultatory diagrams of systolic murmurs. Ejection systolic murmur (top) begins shortly after the first heart sound (S1) and ends shortly before the second heart sound (A2, aortic component and P2, pulmonary component) whereas a holosystolic murmur (bottom) begins with and obscures the S1 and may last throughout the systole (as in the diagram) or

The timing of the click, the extent of splitting of the second sound, the intensity of the pulmonary component of the second sound, the length (duration) of the murmur, and timing of peaking of the systolic murmur are usually suggestive of the severity of

The loudness of the ejection systolic murmur does not indicate the severity of obstruction but rather its duration and time of peaking; the longer the murmur and the later it peaks, the more severe is the PS. Similarly, the shorter the time interval between the first heart sound and ejection click, the wider the splitting of the second heart sound, and softer the pulmonary

In most cases, the chest film shows no cardiomegaly, but a characteristically dilated main pulmonary artery segment (post-stenotic dilatation) is visualized. The magnitude of pulmonary artery dilatation has no bearing on the severity of pulmonary valve stenosis.

The ECG shows right ventricular hypertrophy; the degree of right ventricular hypertrophy

The echo may show right ventricular enlargement without paradoxical septal motion and thickened and domed pulmonary valve leaflets. The Doppler flow velocity across the site of obstruction is increased and the magnitude of this increase reflects the severity of

is proportional to the severity of stenosis. Right atrial enlargement may be present.

pulmonary valve obstruction (Figure 2) (Rao 1991b, Vogelpoel & Schriere 1960).

component, the more severe is the degree of pulmonary valve obstruction (Rao 2000).

may stop short of A2.

**4.1.3 Clinical assessment of severity** 

**4.1.4 Noninvasive evaluation** 

**4.1.4.2 Electrocardiogram (ECG)** 

**4.1.4.3 Echocardiogram** 

**4.1.4.1 Chest x-ray** 

pulmonary valve stenosis. The peak instantaneous pressure gradient can be calculated by the use of a modified Bernoulli equation:

Δ P = 4 V2

Where, Δ P is peak instantaneous pressure gradient in mmHg and V is the peak velocity across the valve in meters/sec.

Fig. 2. In valvar pulmonary stenosis, severity of obstruction may be judged by auscultatory findings. In mild cases of pulmonary valve stenosis, the click (EC) is clearly separated from the first heart sound, almost normal splitting of the second heart sound with normal or slightly increased pulmonary component (P2) of the second sound is heard, and an ejection systolic, diamond-shaped murmur that peaks early in systole and ends way before the aortic closure of the second heart sound is appreciated. The findings in moderate PS include an ejection systolic click that is much closer to the first heart sound than in milder forms, widely split second sound with diminished pulmonary component of the second sound and an ejection systolic murmur that peaks in mid to late systole and ends just below the aortic component (A2) of the second sound. The features of severe valvar PS are an ejection systolic click which is either not present or falls so close to the first heart sound that it becomes inseparable from it, markedly increased splitting with a soft or inaudible pulmonary component of the second heart sound, and a long ejection systolic murmur that peaks late in systole and extends beyond the aortic component of the second sound so that the latter cannot be heard.

#### **4.1.5 Cardiac catheterization and selective cineangiography**

Though this procedure is not required for diagnosing valvar PS, it is usually required prior to therapeutic intervention, to be discussed below. The oxygen saturation data usually do not show evidence for left-to-right shunts. A right-to-left shunt across the patent foramen ovale (or an atrial defect) may be present in moderate to severe pulmonary valve obstruction. Right atrial pressure (particularly 'a' wave) may be increased. The right ventricular peak systolic pressure is increased. Trans-pulmonary valve peak-to-peak gradient is indicative of severity of obstruction. A peak-to-peak gradient in excess of 50 mmHg is usually considered an indication for therapeutic intervention. Angiocardiography

Congenital Heart Defects – A Review 9

Previous recommendations are to use a balloon that is 1.2 to 1.4 times the size of the pulmonary valve annulus; however, more recent recommendations are to limit the balloon/annulus ratio to 1.2 to 1.25 (Rao 2000b, Rao 2007a, Rao 2007b). When the pulmonary valve annulus is too large to dilate with a single balloon, valvuloplasty with simultaneous inflation of two balloons across the pulmonary valve annulus is recommended. Immediate, short-term and long-term results (Figure 4) are good; although

Fig. 4. Bar graph showing maximum peak instantaneous Doppler gradients, indicative of severity of pulmonary stenosis, prior to (Pre), one day following (Post) balloon pulmonary valvuloplasty and at intermediate-term (ITFU) and late (LTFU) follow-up. Note significant reduction (p 0.001) after valvuloplasty, which remains unchanged (p 0.1) at ITFU.

Given the success with balloon pulmonary valvuloplasty, surgery is reserved for unsuccessful balloon cases, mostly for cases with supravalvar PS, severe valve annular

In patients with mild pulmonary valve stenosis, periodic clinical follow-up, antibiotic prophylaxis prior to any bacteremia-producing procedures to prevent subacute bacterial

Left ventricular outflow tract obstruction may occur at valvar, subvalvar (fixed subaortic stenosis and idiopathic hypertrophic subaortic stenosis) and supravalvar locations (Singh and Rao 2009). Valvar stenosis is the most common form and will be discussed in this section. The prevalence of congenital valvar aortic stenosis (AS) is 5% to 6% of patients with CHD. The pathology of the stenotic aortic valve is variable, most commonly it is a bicuspid valve with varying degrees of commissural fusion of thickened, domed, nonpliable valve leaflets. Tricuspid and rarely unicuspid aortic valve leaflets can also cause aortic valve obstruction. Dysplasia of the aortic valve leaflets with or without hypoplasia of the valve ring may be found in neonates and young infants. Calcification of

However, at LTFU there was further fall (p 0.01) in the Doppler gradients.

long-term results are limited (Rao et al 1998).

hypoplasia and dysplastic pulmonary valves.

**4.2 Aortic stenosis** 

endocarditis and no exercise restriction are recommended.

usually reveals thickened and domed pulmonary valve leaflets with a thin jet of passage of contrast across the pulmonary valve. Enlargement of the right ventricle and dilated main pulmonary artery segment are also seen. In patients with severe or long-standing pulmonary valve obstruction, infundibular constriction may be seen.
