To our knowledge, this is the first report of PV isolation (PVI) for a rescue purpose applied in a patient with hemodynamically unstable AF complicated with an AMI. The present case includes two major findings. First, AF may be triggered by ectopies from the PVs in the critical setting of AMI. Second, PVI may be effective for rhythm control and may thereby improve hemodynamic status.
AF, especially a new onset of AF, has been shown to be an independent predictor of mortality in patients with AMI
[1, 2]. AF may cause adverse hemodynamic effects, such as loss of atrial contraction, rapid ventricular rates, loss of atrioventricular synchrony, and an irregular RR interval, leading to a decrease in cardiac output
. Thus, when the patients are complicated with congestive heart failure, the development of AF should have greater adverse clinical significance than in cases without heart failure
. Systemic circulation may collapse immediately. Even if it does not, insufficient coronary flow due to decreased cardiac output may lead not only to delaying the myocardial healing process but also to further myocardial damage, which starts a vicious cycle of hemodynamic deterioration. In this setting, AF could be a lethal arrhythmia. The present case is a typical example. The hemodynamics were barely maintained during sinus rhythm with the mechanical support of an IABP, but they immediately deteriorated due to the development of AF.
Despite the increasing evidence showing the prognostic significance of AF in patients with AMI, current therapeutic strategies in this setting seem to be limited to the management of hemodynamics, including IABP, mechanical ventilation, CHDF, and so forth. In addition, sedation with opioid analgesic drugs such as sufentanil might provide some cardioprotective / antiarrhythmic effects. These are the therapies generally given to AMI patients with congestive heart failure, but are not a specific treatment for AF. The rate control strategy may be accepted as an alternative to sinus rhythm restoration. However, attempts at rate control often fail when patients are on high levels of endogenous or exogenous catecholamines or are not able to tolerate the use of drugs including beta-blockers, digoxin, and calcium antagonists, because these agents have negative inotropic effects or may increase oxygen consumption. Furthermore, sinus rhythm should be necessary to maintain systemic circulation in patients with severe pump failure as shown in the present case. Amiodarone might be a drug that can be used in this setting
. However, observational data recently suggested that an amiodarone-based rhythm control strategy in patients with AF after AMI complicated by heart failure or LV dysfunction is associated with excess early mortality when compared with the rate control strategy
PVI has been accepted by consensus as the strategy of choice for the treatment of AF by catheter ablation
. PVI exerts its beneficial effects by autonomic denervation of LA, by eliminating part of the arrhythmogenic substrate, and most importantly by eliminating AF triggers arising from PVs
[6, 7]. However, it is not clear whether PVI also functions well in the setting of AMI where multiple precipitating factors may be involved in the development of AF. Those factors may include inflammation, acute hypoxia or hypokalaemia, endogenous or exogenous catecholamines, right ventricular infarction, and atrial ischemia
. Hemodynamic impairment secondary to LV dysfunction such as a high pulmonary artery wedge pressure as well as right atrial pressure relate to the development of AF
. The present case demonstrated that PVs play an important role as a source of AF triggers in this setting. PV-stretch due to elevated PV pressure might contribute to the triggering substrate
. Although the patient died due to ventricular fibrillation, PVI successfully brought the patient back into sinus rhythm and clearly improved his hemodynamic status.
Based on this single case report, it is premature to draw conclusions that PVI could become a standard procedure to treat AF in the critical setting of an AMI. Since PVI is still a highly complex procedure, a careful assessment of benefit and risk must be considered for each patient.