EKG findings with Atrial Fibrillation:
- Irregularly irregular rhythm (no RR repetitive pattern)
- No distinct P waves
- f waves (small, irregular waves indicating rapid atrial activity ~150-300 bpm)
Common etiologies of Atrial Fibrillation:
- Ischemic heart disease
- Hypertension
- Thyrotoxicosis
- Drugs (sympathomimetics)
- PE
- Valvular heart disease (esp. mitral stenosis / regurgitation)
- Electrolyte abnormalities (hypokalemia, hypomagnesaemia)
- Cardiomyopathies (dilated, hypertrophic)
Different Classifications of Atrial Fibrillation:
- Paroxysmal: AF that terminates spontaneously or with intervention within 7 days of onset
- Persistent: sustained AF that lasts > 7 days
- Long-standing persistent: sustained AF that lasts > 12 months
- Permanent: persistent AF with either treatment failure or a decision to not pursue treatment
CHADS2 versus CHA2DS2VASc:
CHADS2 = CHF (1), HTN (1), Age ≥ 75 years (1), DM (1), Stroke/TIA (2)
CHA2DS2VASc = CHF (1), HTN (1), Age ≥ 75 years (2), DM (1), Stroke/TIA (2), Vascular disease (1), Age 65-74 (1), Female sex (1)
- Treat with anti-coagulation is score >2
- Treatment options include: warfarin (goal INR 2-3), dabigatran, rivaroxaban, apixaban
Rate versus Rhythm Control:
AFFIRM trial
- In patient’s with non-valvular AF, there is no survival benefit between rate and rhythm control
- A non-significant trend towards decreased mortaility was associated rate control
Strict versus Lenient rate control:
RACE II trail
- Among patients with permanent atrial fibrillation, lenient rate control (HR <110 bpm) is as effective as strict rate control (HR < 80 bpm) in preventing cardiovascular events
- Of note, the strict group met resting targets in 78% of cases (compared with 98% in lenient) and required 9 times as many visits (684 vs. 75)
Physical Exam of Thryotoxicosis:
Skin: warm/moist skin, thin/fine hair, pretibial myxedema (Grave’s disease), thyroid acropachy (digital clubbing, swelling of digits)
Eyes: stare (lid retraction), lid lag, exophthalmos, periorbital/conjunctival edema, limitation of eye movement
CV: tachycardia, atrial fibrillation, systolic hypertension, high output CHF
GI: increased appetite, hyperdefecation
Neuro: fine tremor, hyperreflexia, proximal muscle weakness
Psych: anxiety, agitation, psychosis, depression, insomnia, mania
Thyroid: diffuse thyromegaly, thyroid bruit (specific for Graves)
Graves’ Disease | Toxic adenoma / TMNG | Subactue Thyroiditis | |
Epidemiology | Females between 20-50 yo | TA – 40-50 yo; TMNG > 50 yo | Female > Male; young > old |
Pathophysiology | Antibodies against TSH receptors (TSI or TRAb) stimulate autonomous production of T4/T3 | Autonomous production from activating mutations in TSH receptor | Leakage of hormone from gland |
Clinical Course / Physical Exam | Exophthalmos,
Pre-tibial myexedema, Thyroid bruit |
Hyperthyroid symptoms;
Palpable nodule(s) |
Often preceded by URI, painful thyroid palpation, initially hyperthyroid => hypothyroid => normalizes |
Diagnosis / Tests | Low TSH, High FT4/T3, TSI, TBII; RAIU with markedly increased activity | TSH, FT4, RAIU, thyroid US | TSH, FT4
RAI – low uptake Thyroid US – diffuse enlargement |
Treatment | Thionamides (PTU, methimazole); RAIA (avoid with ocular findings), surgery | Thionamides (toxic patients), surgery for compression, RAIA | NSAIDs, supportive care; prednisone if poor response, BB for symptom management |