We have two options to manage AF.Rate or rhythm control .(Of course , in the strict sense , rhythm control also confers rate control that is built in-situ with SR ) .There was an initial confusion which strategy would fare better .For a decade or so rhythm control was thought to be supreme. That’s logical to expect as we restore physiology in the later .” We know, medical science often disrespects logic , and scientists reinvent this harsh fact in regular fashion” Now , we have clear, consistent data that proved rate control is a better strategy in most situations of AF .(AFFIRM, RACE 1 and 2 studies). The aim of treatment of AF are the following .
- Improve symptoms of palpitation
- Improve hemodynamics
- Reduce MVO2 and hence avoid ischemia
- Prevent tachycardic cardiomyopathy in the long-term
- Avoid stroke .
Unfortunately or fortunately rate control strategy was able to fulfill all these aims with fair degree of success. There are at-leaset 3 reasons why rhythm control fared poorly .
- Rhythm control is actually a myth. Only about 35 % patients remained in SR at any time in rhythm control .Runs of transient AF can occur at any given day* and make a mockery of the much hyped rhythm control !(*Due to heightened adrenergic tone or adverse biochemistry/ hypoxia)
- The drugs used to maintain SR are far more toxic . The complex EP procedures to convert to SR has not helped either.
- Most importantly , rate control with anticoagulants were able to achieve better stroke reduction than rhythm control group.The reason being stroke risk was unabated even if rhythm is back to sinus, as risk of ischemic stroke continue to emanate from as many sites like aorta, aortic arch and carotid. Hence, in a stroke prone population with AF , it is the meticulous anticoagulant that’s is going to prevent strokes rather than rhythm control .Since the rhythm control patients would need to continue anticoagulants , they lose a presumed logical therapeutic advantage.