Ventricular Septal Defect

Ventricular Septal Defect

1. VENTRICULAR SEPTAL DEFECT Dr. Sayeedur Rahman Khan Rumi [email protected] MD Final Part Student NHFH&RI

2. Introduction A ventricular septal defect (VSD) is a hole or a defect in the septum that divides the 2 lower chambers of the heart, resulting in communication between the ventricular cavities. VSDs were first clinically described by Roger in 1879.

3. Incidence & Prevalence A VSD is the most common congenital cardiac anomaly. It may be an isolated defect or part of a complex malformation . The incidence of VSDs is approximately 2 per 1000 live births . Prevalence among school-age children has been estimated as 1 per 1000. Males and females are affected equally.

4. Association C oarctation of the aorta ASD PDA Intracardiac obstructions such as- S ubpulmonary or subaortic stenosis M itral stenosis, and A nomalous muscle bundle of the right ventricle Incompetent atrioventricular valves.

5. ANATOMY

6. Classification: Based on anatomical location A small membranous portion and A large muscular portion: T he inlet septum, T he outlet septum T he trabecular septum: Anterior Posterior Mid Apical

7. Perimembranous defects The membranous defect involves varying amounts of muscular tissue adjacent to the membranous septum ( perimembranous VSD). According to the accompanying defect in the adjacent muscular septum, perimembranous VSDs have been called perimembranous inlet, perimembranous trabecular , or perimembranous outlet (tetralogy type) defects. Perimembranous defects are most common (70%).

8. Perimembranous inlet (“ AV canal-type”) VSD P erimembranous trabecular VSD P erimembranous infundibular VSD Inlet muscular VSD Trabecular muscular VSD Infundibular or outlet muscular VSD Subarterial infundibular ( supracristal ) VSD

9. The “Swiss cheese” type of multiple muscular defect (involving all components of the ventricular septum) is extremely difficult to close surgically .

10. Gerbode defect Located in the membranous portion of the atrioventricular septum. A Left Ventricular to Right Atrial defect. Uncommon , small.

11. Classification: Based on size S mall VSD: defect size is less than one-third of the size of the aortic root, Moderate VSD: defect size is less than one-half of the size of the aortic root, and Large VSD: defect size is equal to or larger than the size of the aortic root.

12. Classification: Based on Pressure Restrictive VSD: Qp /Qs ≤ 1.4:1 Moderately restrictive VSDs: Qp /Qs = 1.4 to 2.2:1 Nonrestrictive VSDs: Qp /Qs > 2.2:1

13. Classification: Based on ventriculography Tubular type Window type Aneurysmal type Infundibular type

14. Embryology Partitioning of the ventricular mass begins as a muscular ridge in the floor of the ventricle near the apex. This ridge later undergoes active growth, which forms the muscular ventricular septum. Concomitantly , the endocardial cushions fuse and the two regions meet, completing closure of the interventricular foramen

15. Natural history Approximately 25% of small defects close spontaneously by 18 months, 50% by 4 years, and 75% by 10 years. A spontaneous closure rate approaching 45% within the first 12 to 14 months has been observed among infants with an uncomplicated perimembranous or muscular VSD in the neonatal period. Even large defects tend to become smaller . Defects close by two mechanisms: by muscular septum growth and by “aneurysmal tissue” from a septal leaflet of the tricuspid valve as in the case of perimembranous defects.

16. Natural history (Contd.) Endocarditis is a risk because of the presence of a high-velocity, turbulent jet into the right ventricle. Endocarditis most frequently involves the septal leaflet of the tricuspid valve apparatus at the point of jet impact.

17. Natural history (Contd.) A large VSD during childhood is typically associated with significant left-to-right shunt and eventual development of congestive heart failure . Patients with moderate-sized VSDs can survive to adulthood before detection. Given the gradual development of symptoms in these patients, they may not present until late in the disease course. In these patients, the excess right-sided flow may lead to pulmonary vascular disease and Eisenmenger physiology if left untreated.

18. Natural history (Contd.) Risk factors for decreased survival include: C ardiomegaly seen on the chest radiograph Elevated pulmonary artery systolic pressure (> 60 mm Hg and/or more than one-half of the systemic pressure ) C ardiovascular symptoms such as shortness of breath, fatigue, or dyspnea on exertion; and P rogressive aortic insufficiency

19. Clinical Manifestations

20. History With a small VSD, the patient is asymptomatic with normal growth and development. With a moderate to large VSD, delayed growth and development, decreased exercise tolerance , repeated pulmonary infections, and CHF are relatively common during infancy . With long-standing pulmonary hypertension, a history of cyanosis and a decreased level of activity may be present.

21. Physical Examination Infants with small VSDs are well developed and acyanotic . Before 2 or 3 months of age , infants with large VSDs may have poor weight gain or show signs of CHF. Cyanosis and clubbing may be present in patients with pulmonary vascular obstructive disease ( Eisenmenger’s syndrome ).

22. Precordium A systolic thrill may be present at the lower left sternal border. Precordial bulge and hyperactivity are present with a large-shunt VSD. The intensity of the P2 is normal with a small shunt and moderately increased with a large shunt. The S2 is loud and single in patients with pulmonary hypertension or pulmonary vascular obstructive disease.

23. A grade 2 to 5 of 6 systolic murmur is audible at the lower left sternal border. It may be holosystolic or early systolic. An apical diastolic rumble is present with a moderate to large shunt. With infundibular VSD, a grade 1 to 3 of 6 early diastolic decrescendo murmur of AR may be audible.

24. Electrocardiography With a small VSD, the ECG findings are normal. With a moderate VSD, left ventricular hypertrophy (LVH) and occasional left atrial hypertrophy (LAH) may be seen. With a large defect, the ECG shows biventricular hypertrophy (BVH) with or without LAH. If pulmonary vascular obstructive disease develops, the ECG shows RVH only .

25. BVH. Large biphasic QRS complex V2-V5. Katz- Wachtel phenomenon

26. Radiography Cardiomegaly of varying degrees is present and involves the LA, left ventricle (LV ), and sometimes RV. Pulmonary vascular markings increase. The degree of cardiomegaly and the increase in pulmonary vascular markings directly relate to the magnitude of the left-to-right shunt . In pulmonary vascular obstructive disease, the main PA and the hilar PAs enlarge noticeably , but the peripheral lung fields are ischemic.

27. Echocardiography Two-dimensional and Doppler echocardiographic studies can identify : Number , size, and exact location of the defect E stimate PA pressure by using the modified Bernoulli equation I dentify other associated defects and E stimate the magnitude of the shunt.

28. L ocation of the various types of VSD when viewed using 2D Echo

29. In the standard parasternal long-axis view (A1), the ventricular septum consists of (from the aortic valve toward the apex) the infracristal outlet ( Inf -C outlet) septum (the VSD of tetralogy of Fallot is seen here) and the trabecular (mid- and apical) septum. In the parasternal right ventricular outlet tract (RVOT) view (A2), the septum consists of supracristal outlet (Sup-C outlet) septum and the trabecular septum. In the parasternal short-axis view showing the aortic valve (B1), the membranous septum is toward the 10 o’clock direction, the infracristal outlet septum at the 12 o’clock direction, and the supracristal outlet septum immediately adjacent to the pulmonary valve. The ventricular septum at the mitral valve (B2), the posterior muscular septum is inlet (INLET) septum. The ventricular septum at the papillary muscle (B3) is all trabecular septum, so that one can easily classify the defect into anterior (ANT), mid- (MID), and posterior (POST) trabecular defects. In the apical four-chamber view showing the coronary sinus (C1), the ventricular septum is the posterior (POST) trabecular septum. In the apical four-chamber view showing both atrioventricular (AV) valves (C2), the septum immediately beneath the tricuspid valve is the inlet septum (INLET) and the remainder is the mid- and apical septa. The thin septum between the insertion of the mitral and tricuspid valves is the AV septum (C2), a defect which can result in a left ventricle (LV)–to–right atrium (RA) shunt. In the standard apical four-chamber view, the membranous septum is not visible. In the apical “five-chamber” view (C3), the membranous (MEMB) septum is seen beneath the aortic valve, and below it is the infracristal outlet ( Inf -C outlet) septum.

30. The ventricular septum seen in the subcostal four-chamber view (D1) is similar to the apical four-chamber view (C2). With anterior angulation of the horizontal transducer, the LV outflow tract (LVOT) is seen (D2), and the septum seen here is similar to the apical “five-chamber” view (C3). With further anterior angulation, the RVOT is seen (D3). The superior part is the supracristal outlet (Sup-C outlet) septum, and the inferior part is the anterior (ANT) trabecular septum (D3 ). The subcostal short-axis view showing the RVOT (E1) is orthogonal to the standard subcostal four-chamber view and is an important view for evaluating the site and size of a VSD. In this view, both supracristal outlet ( Sup-C outlet ) and infracristal outlet ( Inf -C outlet) septa (in that order) are seen beneath the pulmonary valve and the trabecular septum (ANT and POST) is seen apical ward. The ventricular septum seen at the papillary muscle ( E2) is all trabecular septum and is similar to the parasternal short axis view (B3).

31. Cardiac Cath Shows an increase in oxygen saturation at the right ventricular level and pulmonary artery level , reflecting the left-to-right ventricular shunt. With small defects, the right ventricular and pulmonary arterial systolic pressures are normal. With large defects, these pressures are at or near systemic levels. LV graphy : to determine the exact site, size, and number of septal defects. to establish the spatial relations of the great arteries to each other and to the ventricles. Aortography: PDA, CoA

32. LV graphy

33. Management

34. Medical Treatment of CHF: Rest O2 inhalation Diuretics Digoxin Vasodilators Prophylaxis for IE No exercise restriction is required in the absence of pulmonary hypertension.

35. D evice closure Trabecular VSDs have proved more amenable to this technique because of their relatively straightforward anatomy and a muscular rim to which the device attaches well and therefore results in excellent closure rates with low procedural mortality. Closure of perimembranous VSDs is technically more challenging because of their proximity to valve structures ; careful patient selection is required.

36. The Amplatzer muscular VSD occluder consists of three components: an LV disk, a connecting waist, and an RV disk . Polyester fabric is present in both disks and the connecting waist.

37. Complications of Device closure Device embolization Arrhythmias Air embolism Hemolysis Valvular regurgitation Heart block

38. Surgical Indications: A significant L-R shunt with Qp /Qs of greater than 2:1 is an indication for surgical closure. Surgery is not indicated for a small VSD with Qp /Qs less than 1.5:1.

39. Timing: Infants with CHF and growth retardation unresponsive to medical therapy should be operated on at any age, including early infancy. Infants with a large VSD and evidence of increasing PVR should be operated on as soon as possible. Infants who respond to medical therapy may be operated on by the age of 12 to 18 months. Asymptomatic children may be operated on between 2 and 4 years of age. Contraindications : PVR/SVR ratio of 0.5 or greater or PVOD with a predominant R-L shunt.

40. Procedure PA banding as a palliative procedure is no longer performed unless additional lesions make complete repair difficult. Direct closure of the defect is carried out under hypothermic cardiopulmonary bypass, preferably without right ventriculotomy . Most perimembranous and inlet VSDs are repaired by a transatrial approach. Outlet ( conal ) defects are best approached through an incision in the main pulmonary artery. Apical VSD may require apical right ventriculotomy .

41. Transatrial repair of VSD

42. Mortality The surgical mortality rate is less than 1%. The mortality rate is higher for- S mall infants younger than 2 months of age, I nfants with associated defects, and I nfants with multiple VSDs .

43. Complications RBBB is frequent in patients repaired via right ventriculotomy . Complete heart block requiring pacemaker occurs in 1% to 2% of patients. Residual shunt occurs in fewer than 5 %. The incidence of neurologic complications is directly related to the circulatory arrest time .

44. Reproductive Issues Pregnancy is well tolerated in women with small or moderate VSDs and in those with repaired VSDs. Pregnancy is contraindicated in women with Eisenmenger syndrome because of high maternal ( ≈50%) and fetal (≈60%) mortality.

45. Thank you