Arrhythmia case: Mr. Palpita is a 63-year-old male presenting to...

Arrhythmia case:

Mr. Palpita is a 63-year-old male presenting to his physician's office complaining of palpitations that he first noticed 7 days ago. He reports that he is aware of the palpitations but that he has remained relatively asymptomatic. There has not been a noticeable change in his level of fatigue or exercise capacity during his normal daily activities. For the past few years, his baseline exercise capacity would be described as slight limitation of physical activity with some symptoms during normal daily activities but asymptomatic at rest. He has a history of AF that was cardioverted to NSR and he has been on amiodarone to maintain NSR for the past 8 months. In the office today, Mr. Palpita's EKG shows that he is in atrial

fibrillation.

PMH++

CHF × 6 years

HTN

Obstructive sleep apnea, alleviated with CPAP therapy++

FH++

Both parents are deceased. Father died from AMI at age 64. Mother died of breast cancer at age 70 years.

 

SH++

Works as an accountant

Married with 2 children

No tobacco use. Drinks a few beers on the weekend.

 

Meds++

Carvedilol 6.25 mg PO twice daily

Digoxin 0.0625 mg PO daily

Amiodarone 200 mg PO once daily

Furosemide 20 mg PO once daily

KCl 20 mEq PO once daily

Lisinopril 10 mg PO once daily

Warfarin 5 mg PO once daily

CPAP therapy at night

Allergies:++ NKDA

 

ROS++

Reports no change in level of fatigue, some exercise intolerance; no headache, lightheadedness, chest pain, angina, or fainting spells; 2+ pitting edema.

 

PE:

Gen - pleasant, no apparent distress

VS:     BP: 158/92 mmHg     HR: 110 bpm (irregular)                     RR: 18            Temp: 36.3C

Weight: 238 lbs (108 kg)       Height: 5'11"                                    BMI 33

Physical exam -

normal S₁, S₂, (+) S₃, no S₄

Pulses 1+ weak, full ROM, no clubbing or cyanosis; mild edema (2+)

9-Pathophysiology: Describe how AF affects cardiac output.

10-Therapeutics: Is this patient's heart rate controlled to goal for atrial fibrillation? What is the goal?

11-Pharmacology: Amiodarone is known to have many drug interactions. Explain the effects of amiodarone on several key P450s and P-glycoprotein and how those effects result in drug interactions.