Old and New Inferior Infarction

Report:

Sinus bradycardia 44/min

First degree AV block

Right bundle branch block

Acute inferior infarction

Comment:

The splayed, low-amplitude P waves are difficult to time with respect to possible 2:1 block at 88/min. Even isorhythmic AV dissociation cannot be discounted. The trace below, with right-sided leads to demonstrate right ventricular infarction, looks more like sinus tachycardia with 2:1 block, but, again, without great certainty. At any rate (no pun intended), there was enough bradycardia and deprivation of atrial transport (even with long first-degree block 0.44”) to contribute significantly to the circulatory shock the patient was in.

The inferior Q waves were present before the current infarction but this could not be told from this trace alone. The RBBB was new and testified to the right ventricular involvement, as does the lack of any ST depression in V1, expected either from RBBB per se or reciprocally to inferior MI.

The next two pages (Figs 67a, 67b) show temporary bipolar pacemaker rhythm 68/min with interpolated, perhaps pacemaker-induced, VEBs in alternate cycles and his ECG with right-sided leads. Acute inferior infarct ST/T pattern is seen in the frontal leads even in paced rhythm.[! XE "Trigeminy:interpolated VEB!]

The patient survived prolonged dialysis and even longer ventilation in ICU to be discharged to a nursing home, where he died a few months later, with by then a permanent pacemaker.