The U.S. Food and Drug Administration (FDA) recently approved the HEAL-IST Trial (U.S. FDA IDE# G210309) to evaluate a sinus node sparing hybrid ablation procedure for the treatment of patients suffering from inappropriate sinus tachycardia. These patients have heart rates which typically range over 100 beats per minute even at rest.

We at Memorial Health are pleased to be one of the sites enrolling in this landmark clinical trial. The Hybrid Epicardial and Endocardial Sinus Node Sparing Ablation Therapy for Inappropriate Sinus Tachycardia (HEAL-IST) Trial will determine if a sinus node sparing hybrid ablation approach can safely and effectively reduce elevated heart rate and potentially improve quality of life among symptomatic drug refractory or drug intolerant patients with this arrhythmia.

This procedure is an epicardial-endocardial minimally invasive hybrid ablation which has shown promise in treating symptomatic drug refractory or drug intolerant patients with IST.1,2

Inappropriate Sinus Tachycardia (IST) is a debilitating condition in otherwise healthy patients, resulting in a significant loss in quality of life.3 IST is characterized by an elevated heart rate of >100 bpm at rest with spikes of the heart rate well over the normal range during mild exertion. Common complaints with IST include palpitations, lightheadedness, pre-syncope, syncope, orthostatic intolerance, chest pain/pressure, dyspnea, and exercise intolerance.4 

Mechanisms for IST are believed to amount to a form of dysautonomia, an intrinsic sinus node problem, or both.3

Estimates of IST prevalence vary from 1% to 1.2% of the general population and occurs mostly in young females.  Because IST is not always recognized, many patients are misdiagnosed with panic attacks and mental or emotional disorders.2,3

Pharmacotherapy including beta blockers, calcium channel blockers and ivabradine remains first line treatment for patients suffering from IST, however response rates are typically sub-optimal even with prolonged therapy.1,5 However, a study has recently been published which evaluated hybrid ablation against traditional sinus node modification in drug resistant or intolerant patients with IST. The study demonstrated greater reductions in mean daily heart rate through 12 months with hybrid ablation compared to sinus node modification via endocardial radio frequency (RF) ablation alone.1 This study shows preliminary positive impact of the hybrid procedure, and the results of the HEAL-IST trial will further gather safety and effectiveness data.