Interesting Cases: Bahman Arrhythmia Clinic : Tachycardai induced cardiomyopathy resulting from incessant AVRT in a 72 years old man

Title: Tachycardai induced cardiomyopathy resulting from incessant AVRT in a 72 years old man

A 72 years old man with a history of palpitation for 2 years and recent dyspnea and orthopnea was referred to us because of incessant SVT. Coronary angiography has revealed normal coronary arteries 3 month before referral and trans- thoracic echocardiogram demonstrated LVEF of about 35%.

Surface 12 lead ECG showed an incessant regular narrow complex tachycardia with a rate of about 160 bpm(fig 1).The patient has never been referred for EP workup and drugs such as verapamil,sotalol,betablockers and even amiodarone had been prescribed without success.

figure 1

According to the old age and cardiomyopathy the most acceptable mechanism which can be considered in this patient is atrial tachycardia; However after placement of diagnostic catheters we surprisingly found an incessant AVRT using a left free wall concealed accessory pathway (fig 2).The diagnosis of AVRT was confirmed by advanced retrograde conduction by ventricular pacing while His refractoriness during arrhythmia (fig 2).The SVT was just transiently terminated by atrial overdrive pacing. During sinus rhythm ventricular pacing revealed eccentric retrograde conduction through left free wall concealed AP with a refractory perid of 300 msec (which is relatively long).

fig 2. intracardiac tracing during SVT.advancement of retrograde conduction by v pacing also showed

The catheter of ablation was placed trans-septally in mitral ring (fig 3) and the best fused potential during ventricular pacing was found in a lateral region in which RF ablation resulted in cessation of retrograde conduction through AP(fig 4). After 1 month of follow-up the patient is completely asymptomatic and the last echocardiogram demonstrated LVEF about 50%. So it can be concluded that the impaired LV function before ablation was tachycardia induced cardiomyopathy which fortunately was reversible.

figure 3. LAO view.diagnistic catheters in HRA,RV and deep CS and catheter of ablation trans septally placed in the mitral ring

fig 4. successful ablation (abolished retrograde conduction through AP)

This case was particularly interesting due to the unusual presentation of such an incessant AVRT in an old man without any history of palpitation before. Incessant AVRT although is rare but if occurs ,it's typically seen in a fetus, neonate or a young child and as our knowledge we did not find in literature any case of incessant AVRT resulting in cardiomyopathy in old age. May be the most reasonable justification for this strange presentation would be senile changes in conduction properties of AP and AVN which by slower conduction in each of the reentrant limbs , the reentrant wave arrives to the another limb when it's recovered from refractory period and so the condition for incessant reentry becomes provided .

Dr B Faghfurian MD

Dr A Kharazi