LAUSR

Considering the change in P-wave morphology from an inferior to a superior axis as targeted Introduction Inappropriate sinus tachycardia (IST) is a syndrome defined by unexpectedly fast sinus rates at rest or at minimal physical activity. Symptoms include palpitation, exercise intolerance, incapacity to work, fatigue, dizziness, and presyncope. Formatting... please waitMost affected patients are young and female. Formatting... please waitPharmacologic therapy is frequently insufficient despite the fact that multiple drugs are simultaneously administered in the majority of patients. Catheter ablation (CA) offers a further treatment option; yet, limited data is available, and the optimal procedural endpoint has not been identified. The aim of this study was to assess clinical outcomes of sinus node (SN) ablation for the treatment of drug-refractory IST. procedural endpoint can be effective even for patients who did not respond to sinus node modification. Case report Patients Three consecutive patients (aged 28, 36, and 53 years, all women) with highly symptomatic, drug-refractory IST underwent CA aiming at ablation of the SN. IST was defined as a heart rate of.100 beats per minute (bpm) at rest or minimal physical activity. Right atrial activation showed a highto-low activation sequence that was similar during IST and sinus rhythm at normal heart rate. Atrial pacing did not terminate or change the tachycardia cycle length. No potentially reversible causes for sinus tachycardia were identified. Within the last 36 months the patients were hospitalized at least 3 (maximum 5) times. Two patients were unable to work because of their IST. Between 3 and 5 antiarrhythmic drugs had failed to provide sufficient symptom control. Two patients had undergone an ablation procedure for the treatment of IST 60 and 62 days, respectively, prior to the current procedure. The procedural endpoint of the preceding ablation