An adult pt is admitted due to SOB and managed as CHF. Echo showed EF in the 30's.
The basic rhythm is sinus (initial rate ~80's-100s) then there is abrupt decrease of rate (~ 50's bpm) with a slightly different P wave morphology (but still a normal PRI).
The differential diagnoses are:
1. Inappropriate sinus tachycardia (IST)
2. Atrial reentry tachycardia (ART)near the sinus node
3. Sinoatrial reentry tachycardia (SART/SNRT)
IST is non-paroxysmal, elevated resting rate and gradual (excessive acceleration as reaction to mild exercise.However, as we see in the strip, this is paroxysmal. Thus, IST is ruled-out.
ART - paroxysmal and difficult to differentiate from SART.
Sinus node reentry is defined as a reentrant tachycardia involving the sinus node and perinodal tissue. It is possible that SNRT may represent a high cristal atrial tachycrdia (AT) originating near the sinus node . The features of SART/SNRT are:
The features of SART/SNRT are:
1. Abrupt onset/termination (may have gradual slowing)
2. Similar p-wave morphology compared to regular sinus beats (or may differ slightly)/ upright in leads II, III and aVF
3. Rate may vary from 80-140 bpm (ave apprx 100-110)
Thus, this is ART vs SART/SNRT.
Das and Zipes. 2012. Electrocardiography of arrhythmias : a comprehensive review. Elsevier PA
Fisch C and Knoebel SB. 2000. Electrocardiography of Clinical Arrhytmias. Futura Pub NY
Mohammad-Reza et al.1985 Sinus Node Reentry: Case Report and Review of Electrocardiographic and Electrophysiologic Features. Texas Heart Institute 12(3) 249-252 - http://www.ncbi.nlm.nih.gov/.../pdf/thij00003-0044.pdf
Sanders et al. 1994. Catheter Ablation of Sinus Node Reentry Tachycardia. JACC 23 (4) 926-934
Simmers TA and Seeram N. 2003. Sinoatrial Reentry Teacycardia: A Review. Indian Pacing and Electrophsiology 3(3):109-116 - http://www.ncbi.nlm.nih.gov/.../PMC.../pdf/ipej030109-00.pdf