The correct answer is “Pulmonary thromboembolism”

The ECG shows “Sinus tachycardia” and “S1Q3T3 pattern”, two most common ECG findings in PTE. These findings are neither sensitive nor specific for PTE, Thus ECG findings only in combination with physical symptoms suggest PTE.

Here are the most common ECG findings in patients with PTE:

• Sinus tachycardia
• S1Q3T3 pattern
• New-onset atrial fibrillation or flutter
• incomplete right bundle branch block
• right axis deviation
• T-wave inversion in leads V1 to V4

#case196 ❤️

55 y man with history of mitral valve replacement presented with palpitation

The correct answer is “Atrial flutter”

ECG features:
• Inverted flutter waves in Inferior leads at a rate of 350 bpm
• Upright flutter waves in V1 simulating P waves
• 2:1 AV block resulting in a ventricular rate of 175 bpm

55 y man with history of Ischemic heart disease presented with occasional dizziness.

The correct answer is “Second degree AVB: mobitz 1 (Wenckebach)”

ECG features:
• QRS complexes cluster into groups, separated by short pauses. At the end of each group is a non-conducted P wave (dropped beats)
• The PR interval progressively increases from one complex to the next.
• The P-P interval is relatively constant despite the irregularity of the QRS complexes.

65 y female with history of heart failure presented with palpitation

The correct answer is “Atrioventricular nodal reentry tachycardia (AVNRT)”

In the beginning, there are sinus beats that are conducted with 1st degree AV block. These beats are followed by ectopic atrial contractions which are not conducted through AV node (blocked PACs). However, an ectopic atrial contraction eventually triggers an AVNRT, a regular narrow complex tachycardia with relatively long RP intervals due to slow conduction through retrograde pathway in the AV node.

Special Thanks to my dear friend salvatore salvatore for providing the diagram.