ECG 1 is from a 57-year-old male with no prior cardiac disease. He reports acute shortness of breath for 2 days. We see a sinus rhythm with left anterior fascicular block (LAFB) and conspicuous T-wave inversions in the inferior leads and in V1-V6. These are typical ECG changes that may indicate a pulmonary embolism. ECG 2 was taken from the same patient 1 year earlier. The patient has an acute pulmonary embolism. Sinus tachycardia may be present in acute pulmonary embolism. However, as in this example, the heart rate can also be completely normal.

Why is this left atrial atypical atrial flutter (ECG 1)? Atrial fibrillation can be excluded because nice flutter waves (all look the same) can be clearly identified. With typical right atrial flutter, the reentry circle runs counterclockwise and we see typical saw tooth patterns in the inferior leads (negative flutter waves). The flutter waves are positive in V1 (ECG 2). With typical right atrial flutter with a clockwise reentry circle, the flutter waves in the inferior leads are positive.

This Holter-ECG comes from a 70-year-old physician with coronary artery disease. He is twelve months after PCI (RCA, RCX). Currently no symptoms (no dyspnea, no chestpain, no palpitations). You can see that an overview/section from a Holter- EKG, 3 channels are shown, strip width is 30 seconds. First you can see a sinus rhythm with frequent PVCs, then there is a transition to an accelerated idioventricular rhythm (AIVR) that lasts almost a minute in total. 

This ECG is from an 80-year-old lady who has collapsed or had sycopal episodes several times. The ECG comes from a Holter monitor. She has arterial hypertension and coronary artery disease. The ECG shows a second-degree, Mobitz Type II AV block. In both types of AVB, the PP intervals are usually the same.