48-year-old man with chest pain, nausea, and diaphoresis.
VS: BP 96/50 HR 40 R 22 O2 96%
Interpretation & Explanation
Rhythm: progressive lengthening of the PR intervals, until a P wave is dropped 2° AV block, Type I
PR: progressive lengthening with AV block
Chamber enlargement: none
Ischemia/Infarction: broad T waves in inferior leads (II, III, aVF) which begin at the J point of the QRS and seem to be “tugging” the ST-segment upwardà these broad and tall T waves are early, hyperacute T waves of transmural infarction. There are also “reciprocal changes” in V2-3 with ST-segment depression and T-wave inversion. These changes often represent infarction of the posterior wall.
Interpretation: This EKG represents an acute inferior-posterior MI with 2° AV block, type I (Wenckebach).
72-year-old nursing home resident sent to ER for evaluation of fever. Why is his pacemaker firing at a rate of 125/minute?
Answer & Explanation
The pacemaker is firing at a ventricular rate of 125/minute. There is a PVC approximately half-way across the rhythm strip with a compensatory pause which allows you to notice a P wave – and the ventricular pacer follows the atrial activity. This is a dual chamber pacer, which is more physiologic than a single lead ventricular pacemaker. The pacer allows the ventricle to follow the sinus rate during exercise or other situations of appropriate increased heart rate.
Rhythm strip – 4th beat is PVC with following compensatory pause revealing P waves with following ventricular paced beats.
This elder man is febrile and dehydrated – both good reasons for sinus tachycardia at 125/minute. Appropriate treatment of this pacemaker-mediated tachycardia is fluid resuscitation and acetaminophen!
70-year-old woman with dyspnea. What diagnosis belongs on her problem list?
Answer & Explanation
This is an excellent example of EKG changes of COPD.
Findings suggestive of COPD include (but you don’t need to have all):
- P waves >0.25 mV in II, III, or aVF (P “pulmonale”)
- Lead I sign – isoelectric P wave, QRS amplitude <0.15 mV, and T wave <0.05mV in lead I
- QRS amplitude in all limb leads <0.5 mV
- QRS axis > 90° (right axis deviation)
Just in case you’re still not a believer, here’s her CXR…
Note the impressive changes of emphysema: flat and depressed diaphragms and the “vertical” heart.