A 72-year-old female patient with a history of coronary artery disease with stent placement, hypertension, hyperlipidemia, anemia, diabetes, atrial fibrillation, and paroxysmal atrial tachycardia presented to the clinic six weeks following the implantation of an automatic implantable cardioverter-defibrillator (AICD) with complaints of muscle spasms on her back and right side of the chest. The patient reported experiencing a thumping sensation from her back that radiated to the frontal side of her chest. On physical examination, it was noted that the muscle spasms occurred simultaneously with heartbeats and would cease upon laying in a supine position. The muscle spasms also were found to be fainter upon sitting upright and twisting the torso to the right.
The patient denied dyspnea, palpitations, or syncope. She denied previous manual manipulation of her AICD. Vital signs were stable upon presentation. Electrocardiogram revealed a ventricular paced rhythm at a rate of 65 beats per minute (bpm).
Interrogation of the AICD revealed that the right ventricular (RV) lead was not sensing. The percentage of ventricular pacing was 0.2%, in comparison to 10% atrial pacing. P-wave sensing was detected at 0.9 millivolts (mV) while an R-wave was not detected. Fluoroscopy confirmed that the RV lead was coiled around the AICD device and not placed in the right ventricle (Figure 1). Based on these findings, a diagnosis of Twiddler Syndrome was made. The patient underwent AICD system extraction, and an endocardial leadless pacing system was implanted. The post-operative course was uncomplicated.