Cardiomyopathy and Dyssynchrony: The Chicken and the Egg
A 72-year-old female, with a prior history of degenerative joint disease and mild asthma, is admitted to the hospital with CHF. Three years ago she had a normal ECG and echo with an estimated EF of 60-65%. On this admission her ECG showed a first degree AV block (PR of 220-240) and a LBBB. Her echo showed a reduced EF of 30-35% with mild diastolic MR. A MPI showed no scar or ischemia. Troponin, routine viral titers and standard rheumatologic assays were all normal. She was placed on carvedilol, valsartan, spinonolactone and digoxin in optimized doses.
Over the next three months she had one hospitalization and one ER visit for CHF. She has had functional class II-III heart failure symptoms but no palpitations, syncope or documented ventricular arrhythmias. When she returned to you for follow-up after four months of therapy, while in a stable condition, her ECG showed a persistent and progressive first degree AV block (PR of 270-300) and a LBBB. Her echo continued to show a reduced EF of approximately 30-35% with now moderate diastolic MR and a slight increase in the degree of LV enlargement. She was referred for a cardiac cath and MRI. The cardiac cath showed no obstructive CAD (maximal 10-20% luminal irregularities) and moderate MR. The cardiac MRI showed no scar, moderate diastolic MR and an EF of 35-40%. A TDI showed marked intra-ventricular and inter-ventricular dyssynchrony.
When she returns to see you in follow-up what would you recommend?