USMLE Cardio question

[cbrons]

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69 year old man comes for follow-up of ER visit and admission of a few days ago for palpitations and dyspnea. He has a history of CHF and hypertension. He is currently taking hydrochlorthiazide and lisinopril. He appears well and is in no distress. His BP is 130/80 mmHg, pulse 101 and irregularly irregular. Exam reveals mild bibasilar crackles. No gallops. There is a 2/5 holosystolic murmur heard best at the apex. JVP is 10cm at 30 degrees. EKG is below. What's the most appropriate next step?

A.) Defibrillate at 120 joules
B.) Initiate amiodarone
C.) Discontinue lisinopril
D.) Initiate digoxin
E.) Initiate metoprolol
F.) Initiate furosemide

 

[cbrons]

It's not clear to me why the question states "his pulse is 101" when I see R waves spaced that closely on the EKG. Maybe I am stupid. @Instatewaiter

 

[Instatewaiter]

It's not clear to me why the question states "his pulse is 101" when I see R waves spaced that closely on the EKG. Maybe I am stupid. @Instatewaiter

I think they tell you this because on the EKG there are 34 beats in 10 seconds (ie a heart rate of ~192 bpm). This means he is not perfusing on a large percentage of his beats. For instance, when someone is in bigeminy, you often can only feel the pulse on half the beats.

So this guy is either going too fast to perfuse, or more likely going into a non-perfusing rhythm some of the time. It looks like after a normally conducted beat in precordium (ie after 1 beat in V1/V2/V3 he changes axis. So I think they were telegraphing to you that this was happening commonly.

 

[cbrons]

I think they tell you this because on the EKG there are 34 beats in 10 seconds (ie a heart rate of ~192 bpm). This means he is not perfusing on a large percentage of his beats. For instance, when someone is in bigeminy, you often can only feel the pulse on half the beats.

So this guy is either going too fast to perfuse, or more likely going into a non-perfusing rhythm some of the time. It looks like after a normally conducted beat in precordium (ie after 1 beat in V1/V2/V3 he changes axis. So I think they were telegraphing to you that this was happening commonly.

So where do they get 100 from?

 

[Instatewaiter]

When they take his pulse from his wrist (ie the beats that are perfusing enough to cause a pulse) it is 100. The electrical activity by tele/EKG is higher. Thus, some of the electrical impulses are not creating enough stroke volume to cause a palpable pulse.

 

[cbrons]

When they take his pulse from his wrist (ie the beats that are perfusing enough to cause a pulse) it is 100. The electrical activity by tele/EKG is higher. Thus, some of the electrical impulses are not creating enough stroke volume to cause a palpable pulse.

ty

 

[cooldesig8]

digoxin?