DATE OF CONSULTATION: MM/DD/YYYY
REASON FOR CONSULTATION: Supraventricular tachycardia.
HISTORY OF PRESENT ILLNESS: The patient is a (XX)-year-old woman who lives independently. She has a history of pericardial disease and has had a pericardectomy when she was younger. Apparently, according to the patient, she presented with shortness of breath and was found to have constrictive disease. She did well and recovered from that operation and had a normal adulthood with respect to any cardiovascular problems. Six years ago, she underwent permanent pacemaker implantation for sick sinus syndrome and symptomatic bradycardia. She likely had atrial fibrillation as the cause and amiodarone was started around that time. For the last six months to a year, the patient has been doing well and notes no chest pain, shortness of breath, angina, palpitations, dizziness, lightheadedness, or syncope. During a routine office visit to her primary care physician’s office, she was found to have an elevated pulse rate. A 12-lead EKG was performed showing a wide complex tachycardia. Review of the 12-lead EKG in more detail revealed this to be a pacemaker-mediated tachycardia. She was given medication without success and sent to the emergency room. Interrogation of the permanent pacemaker was performed in the emergency room revealing an underlying atrial tachycardia with appropriate tracking. The patient was admitted for observation. Despite receiving adenosine and beta-blockers, her atrial tachycardia persisted with intermittent atrial tracking and pacing. Arrhythmia consultation was requested for further evaluation. The patient is not fully aware of palpitations. She occasionally feels a pounding in her chest. She is not certain when this episode started. She is tolerating amiodarone well and notes no specific side effects.
PAST MEDICAL HISTORY: History of hepatitis secondary to a blood transfusion, polymyalgia rheumatica and thyroid disease, likely due to amiodarone use.
SOCIAL HISTORY: She does not smoke currently but was a heavy smoker approximately 15 years ago. She does not drink alcohol. She is able to walk around with a walker.
FAMILY HISTORY: Noncontributory.
REVIEW OF SYSTEMS: She denies any chest pain, shortness of breath, PND, orthopnea, or palpitations. She complained of bloating and gas in her abdomen. There is no history of cough, fevers, or chills. She has bilateral joint pains and muscle aches. There is no history of stroke or TIA. She denies any dysuria or hematuria. She denies any rashes.
PHYSICAL EXAMINATION:
GENERAL: In no acute distress.
VITAL SIGNS: Blood pressure 102/52, pulse 126 beats per minute, respiratory rate 21 breaths per minute.
HEENT: Sclerae white. Conjunctivae pink. Throat clear.
NECK: No JVD. No bruits. No thyromegaly.
LUNGS: Clear to auscultation and percussion. No wheezes on forced expiration.
HEART: S1 and S2, no murmurs or gallops, tachycardic. No rub is heard.
ABDOMEN: Soft, nontender, nondistended, no masses.
EXTREMITIES: Show 1+ edema bilaterally.
NEUROLOGIC: Alert and oriented.
VASCULAR: Carotids, radials, and dorsalis pedis pulses 2+.
DIAGNOSTIC DATA: A 12-lead EKG shows a narrow complex tachycardia at 126 beats per minute. There are some nonspecific ST-T wave changes. Another EKG shows a wide complex tachycardia consistent with a pacemaker-mediated tachycardia.
LABORATORY DATA: Notable for a normal CBC and basic metabolic profile. TSH is 0.60.
PERMANENT PACEMAKER INTERROGATION: The patient’s pacemaker was interrogated. The baseline rhythm was atrial tachycardia with an atrial rate of 482 msec. The following measurements were obtained in the atrium, including atrial P waves of 2 to 2.9 mV and an impedance of 810 ohms. Following measurements were obtained in the ventricle, including R waves of 11 mV and an impedance of 1300 ohms and a right ventricular threshold of 1.26 volts at 0.53 msec.
IMPRESSION: A patient with a history of sick sinus syndrome, tachycardia-bradycardia syndrome treated with amiodarone and permanent pacemaker implantation. On a routine office visit, she was found to have an elevated heart rate. The 12-lead EKGs have documented an atrial tachycardia with a ventricular response between 120 to 130 beats per minute. She is relatively asymptomatic with respect to this tachycardia. We are not sure of the duration of the tachycardia. Given the atrial rate, it does not meet criteria for mode switching. The best approach at this time would be an attempt at overdrive pacing termination through the pacemaker. If this is successful, continued medical therapy with amiodarone and beta-blockers can be attempted. If she has breakthroughs, one can consider switching her to a calcium channel blocker and/or considering electrophysiologic testing with radiofrequency ablation. If overdrive pacing is not successful, she may require direct current cardioversion. Given that this is an atrial tachycardia with an atrial rate at around 120 to 130 beats per minutes, we do not believe we need to worry about anticoagulation. She is currently on an aspirin and this should suffice.
RECOMMENDATIONS:
1. Pace termination through the pacemaker.
2. Continue amiodarone at 200 mg daily.
3. Continue Lopressor at 50 mg b.i.d.
4. If this is not successful, proceed with direct current cardioversion.
5. If she has recurrent atrial tachycardia, consider changing to a calcium channel blocker and/or consider radiofrequency catheter ablation.
