Subject(s)
Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/therapy , Cardiology , Consensus , Electrophysiologic Techniques, Cardiac/standards , Quality Assurance, Health Care , Societies, Medical , Electrophysiologic Techniques, Cardiac/instrumentation , Humans , Middle Aged , Quality ImprovementABSTRACT
BACKGROUND: We previously proposed that adenosine has mechanism-specific effects on atrial tachycardia (AT), such that adenosine terminates AT attributable to triggered activity, transiently suppresses automatic rhythms, and has no effect on macroreentrant AT. This, however, remains controversial, because other studies have reported that adenosine terminates reentrant AT. To clarify this issue, we used 3D electroanatomic mapping to delineate the tachycardia circuit and thereby determine whether the response to adenosine differentiates focal from macroreentrant AT. METHODS AND RESULTS: We examined the effect of adenosine on 43 ATs in 42 consecutive patients (59+/-15 years of age; 26 female) who received adenosine during tachycardia and whose mechanism of AT was characterized by pharmacological perturbation, entrainment, 3D electroanatomic mapping, and results of radiofrequency ablation. Eight tachycardias were macroreentrant (noncavotricuspid isthmus-dependent), and 35 ATs were focal (either triggered or automatic). Adenosine administered during AT (at doses sufficient to result in AV block) terminated or transiently suppressed focal AT in 33 of 35 cases, whereas 8 of 8 macroreentrant ATs were adenosine insensitive (P<0.001). Twenty-eight of 35 focal ATs were located along the crista terminalis or tricuspid annulus. CONCLUSIONS: The response of AT to adenosine can immediately differentiate atrial tachycardia arising from a focal source from that attributable to macroreentry. This finding can be exploited to facilitate developing a focused, strategic ablative approach at the onset of a procedure.
Subject(s)
Adenosine , Body Surface Potential Mapping , Electrophysiologic Techniques, Cardiac , Heart Atria/physiopathology , Imaging, Three-Dimensional , Tachycardia/diagnosis , Tachycardia/physiopathology , Adrenergic beta-Agonists/administration & dosage , Body Surface Potential Mapping/methods , Cardiac Pacing, Artificial , Catheter Ablation , Diagnosis, Differential , Ebstein Anomaly/diagnosis , Ebstein Anomaly/physiopathology , Electrocardiography , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Tachycardia/classification , Tachycardia/surgery , Treatment OutcomeABSTRACT
OBJECTIVES: The purpose of this study was to define the anatomic distribution of electrically abnormal atrial tissue and mechanisms of atrial tachycardia (AT) after mitral valve (MV) surgery. BACKGROUND: Atrial tachycardia is a well-recognized long-term complication of MV surgery. Because atrial incisions from repair of congenital heart defects provide a substrate for re-entrant arrhythmias in the late postoperative setting, we hypothesized that atriotomies or cannulation sites during MV surgery also contributed to postoperative arrhythmias. METHODS: In 10 patients with prior MV surgery, electroanatomic maps were constructed of 11 tachycardias (6 right atrium [RA], 4 left atrium [LA] and 1 biatrial). Activation and voltage maps were used to identify areas of low voltage, double potentials and conduction block. RESULTS: Lesions were present in the lateral wall of the RA (six of seven maps) and in the LA along the septum adjacent to the right pulmonary veins (four of five maps). In 8 of 10 patients, these findings corresponded to atrial incisions or cannulation sites. Arrhythmia mechanisms were identified for 9 of 11 tachycardias. A macro-re-entrant circuit was mapped in six cases, three involving lesions in the lateral wall of the RA and three involving the LA septum and right pulmonary veins. In three of these cases figure-of-eight re-entry was demonstrated, and in the other three a single macro-re-entrant circuit was observed. In three other cases, a focal origin was identified adjacent to abnormal tissue in the RA (two cases) or within a pulmonary vein (one case). CONCLUSIONS: Surgical incisions for MV surgery provide a substrate for atrial arrhythmias. Both macro-re-entrant and focal mechanisms contribute to AT after MV surgery.