Differential diagnosis, interventions and treatment:
Treatment with the β-blocker cibenzoline and temporal right ventricular
pacing did not relieve the heart failure or severe LVOT obstruction.
Because the patient was at high risk for surgery, we elected to proceed
with urgent PTSMA.
The first to third septal perforator arteries were accessed for ablation
(Figure 2a) using a guidewire (Sion Blue, Asahi Intecc USA Inc., Santa
Ana, CA, USA), then a 1.2 × 6 and
1.5 × 6-mm Mini Trek balloon (Abbott) was inflated. Contrast agent was
selectively injected distal to the occlusive balloon, and simultaneous
transthoracic echocardiography revealed clear delineation of the
proximal septum supplied by this vessel (Figure 2, lower panels).
Absolute alcohol (6.7 mL) was injected distal to the occlusive balloon
over a period of 40 min.
The intraventricular pressure gradient (20 mmHg) and mitral
regurgitation induced by SAM were quickly resolved by PTMA. No
peri-procedural complications developed. Final coronary angiography
after alcohol injection showed occluded target septal arteries and no
damage to the left anterior descending artery (LAD; Figure 2b). Peak
creatinine kinase and creatinine kinase-MB values were 1,693 and 363
IU/L, respectively.