Muscular Ventricular Septal Defect: Follow-up Results in Relation to Anatomic Localisation and Diameter of the Defect in 69 Patients

The median age at start of follow-up was 0.25 years in 69 patients w ith muscular ventricular septal defect (VSD). The duration of follow-up in 80% ranged between 0.1 and 9.7 years. The diameter of the defect ranged between 1-9 mm, and decreased 1.58 mm (±1.60) in 51 patients during the study period. While the ineidence of pulmonary hypertension (PH) and L-R shunt was low, and spontaneous closure ratio was high (54%), in those with defect eliameter ~4 mm, the inverse was true for those with greater defects and non e closed spontaneously. All defects ~4 mm except one, turned to class la or dosed spontaneously, while in those 13 patients with a defect >4 mm, PH continued in 4, shunt remained large in 5 and decreased in 8. Qp: Qs decreased from a mean of 1.77 (±1.04) to 1.34 (±0.80). The most common localisation of muscular defect were apical and midtrabecular, 12 disclosed multiple defects (17.4%). The diameter of the defect was between J- 5.8 mm (mean 3.7) in 29 patients with apical VSD and decreased significantly by 1.60 mm in 23 patients. Qp: Qs decreased from a mean value of I .60 to 1.23 and spontaneous closure occurred in 10 (34.5%). Age at closure ranged between 0.08-13.67 years (median 0.23). On the other hand in 22 patienis with midtrabecular defects , the diameter of the defect ranged between 2-9 mm (mean 3.57) and decreased 1.82 mm. Qp: Qs decreased from 1.45 to 1.16, w hile spontaneous closuı·e occurred in 8 pat ients (36.4%). The age at closuı·e rangecl between 0.08 and 1.25 (median 0.61) years. At onset left-right shunt was mildin 60 out of 69 patients. Both PH and severe shunt were secn in only 7 and none of those closed spontaneously while L-R shunt decreased in 3. The PH in those 29 patients with mild shunting normalised in 13, the defcct dosed spontaneously in 14, and only two reınainccl in the same class. In the 31 patients without PH and mil d shunting, the clefect cl o sed spontaneosly in 1 O, and 21 remained in the same class. Inlet type of defect was observed in two patients in whom the dcfcct was closed surgically. The ineidence of spontaneous closuı·e was 24/69 (34.8%) in the total series. According to median values, the nıuscular defect closed spontaneously in the first 6 months of life. Cunıulative closuı·e ratio was 58% after age 1, 6 1% after age 8 and 64% during adolescence. The dcfcct elianıeter ranged between 1-4 mm in 24 patients whose defect elesed spontaneously (median=3 mm). Qp: Qs was < 1.5 in half of theın and age at closure ranged between 0.08 and 13.67 (median 0.38). It was concluded that prognosis depends not on the the localisation, but on the diameter of the defect.