SHM's Clinical Quick Talks-Approach to Bradycardia

Pdf Summary
Bradycardia refers to a resting heart rate below 60 beats per minute, while bradyarrhythmia indicates a slow heart rate due to an irregular heartbeat. Sinus bradycardia is often observed in healthy adults, particularly athletes and individuals during sleep.<br /><br />**Initial Assessment**:<br />1. **Clinical Examination**:<br />   - **Vitals**: Heart rate (HR), blood pressure (BP), oxygen saturation.<br />   - **Symptoms**: Dizziness, syncope, chest pain, dyspnea, fatigue.<br />   - **History**: Palpitations, chest trauma, recent tick bite, streptococcus pharyngitis.<br />   - **Physical Signs**: Pulmonary edema, altered mental status, shock signs.<br />   - **Risk Factors**: Age, cardiovascular and medication history, electrolyte imbalances.<br />2. **Diagnostic Tests**:<br />   - **12-lead ECG**: Evaluate rhythm, P-wave, PR interval, QRS complex width.<br />   - **Labs**: Glucose, electrolytes, calcium, magnesium, thyroid function, troponin, urine drug screen.<br />   - **Monitoring**: Continuous telemetry, frequent BP monitoring, maintain oxygen above 94%.<br /><br />**Etiologies of Bradycardia**:<br />1. **Cardiac Causes**: Sick sinus syndrome, ischemic heart disease, conduction system disease, genetic disorders.<br />2. **Medications**: Beta-blockers, digoxin, calcium channel blockers, amiodarone, clonidine.<br />3. **Vagal Tone**: Vasovagal syncope, athletes.<br />4. **Metabolic Conditions**: Hypothyroidism, hyperkalemia, hypoxia.<br />5. **Infections**: Endocarditis, myocarditis, Lyme disease.<br />6. **Other Causes**: Obstructive sleep apnea, hypothermia, increased intracranial pressure.<br /><br />**Stability Assessment**:<br />- **Unstable Bradycardia**: Signs include hypotension, shock, altered mental status, ischemic chest discomfort, acute heart failure. Requires immediate resuscitation (ACLS protocols).<br />- **Stable Bradycardia**: Hemodynamically stable with mild/no symptoms. Requires monitoring and assessment for reversible causes.<br /><br />**Management**:<br />- **Unstable Bradycardia**:<br />   - **Medications**: Atropine, dopamine, epinephrine; specific antidotes for drug toxicities.<br />   - **Pacing**: Transcutaneous pacing if unresponsive to medication, followed by transvenous pacing if necessary.<br />- **Stable Bradycardia**:<br />   - **Observation**: Serial ECGs, BP monitoring, correcting reversible causes including electrolyte imbalances and medication toxicity.<br />   - **Specific Antidotes**: Address specific drug toxicities with appropriate antidotes like glucagon or calcium gluconate.<br /><br />**Clinical Pearls**:<br />- Atropine should be avoided in high-grade AV block as it may exacerbate bradycardia.<br />- For symptomatic bradycardia, always have pacing pads ready.<br />- Aggressively manage hyperkalemia in patients with wide-complex bradycardia.
Asset Subtitle
Neel Patel, Sammar Rasheed
Keywords
Bradycardia
Bradyarrhythmia
Sinus bradycardia
Clinical examination
Diagnostic tests
Cardiac causes
Medications
Metabolic conditions
Unstable bradycardia
Management