ABSTRACT
It is important to thoroughly evaluate for anatomical abnormalities that would require surgical management prior to proceeding with a catheter-based intervention. Such abnormalities include anomalous papillary muscle insertion into the mitral valve, anatomically abnormal mitral valve with a long anterior/posterior leaflet, coexistent coronary artery disease, primary valvular disease (aortic or mitral), or subaortic membrane or pannus-none of which can be adequately addressed by septal ablation (Fig. 44.4) (5,51). Furthermore, a subset of patients may be found to have an abnormal elongation and myomatous degeneration of the anterior mitral leaflet resulting in an anterior displacement of the line of coaptation with resultant outflow tract obstruction. These gene-positive HCM patients have dynamic LVOT obstruction from papillary muscle orientation independent of septal hypertrophy (57,58). These patients will require surgical consultation for consideration of myectomy with plication and should not be considered for catheter-based therapy (59). In addition, results of alcohol ablation in patients with severe hypertrophy (i.e., >3.0 cm) are inconsistent, and these patients are frequently referred for surgical correction.
