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 /><strong>Initial Assessment</strong>:<br />1. <strong>Clinical Examination</strong>:<br />   - <strong>Vitals</strong>: Heart rate (HR), blood pressure (BP), oxygen saturation.<br />   - <strong>Symptoms</strong>: Dizziness, syncope, chest pain, dyspnea, fatigue.<br />   - <strong>History</strong>: Palpitations, chest trauma, recent tick bite, streptococcus pharyngitis.<br />   - <strong>Physical Signs</strong>: Pulmonary edema, altered mental status, shock signs.<br />   - <strong>Risk Factors</strong>: Age, cardiovascular and medication history, electrolyte imbalances.<br />2. <strong>Diagnostic Tests</strong>:<br />   - <strong>12-lead ECG</strong>: Evaluate rhythm, P-wave, PR interval, QRS complex width.<br />   - <strong>Labs</strong>: Glucose, electrolytes, calcium, magnesium, thyroid function, troponin, urine drug screen.<br />   - <strong>Monitoring</strong>: Continuous telemetry, frequent BP monitoring, maintain oxygen above 94%.<br /><br /><strong>Etiologies of Bradycardia</strong>:<br />1. <strong>Cardiac Causes</strong>: Sick sinus syndrome, ischemic heart disease, conduction system disease, genetic disorders.<br />2. <strong>Medications</strong>: Beta-blockers, digoxin, calcium channel blockers, amiodarone, clonidine.<br />3. <strong>Vagal Tone</strong>: Vasovagal syncope, athletes.<br />4. <strong>Metabolic Conditions</strong>: Hypothyroidism, hyperkalemia, hypoxia.<br />5. <strong>Infections</strong>: Endocarditis, myocarditis, Lyme disease.<br />6. <strong>Other Causes</strong>: Obstructive sleep apnea, hypothermia, increased intracranial pressure.<br /><br /><strong>Stability Assessment</strong>:<br />- <strong>Unstable Bradycardia</strong>: Signs include hypotension, shock, altered mental status, ischemic chest discomfort, acute heart failure. Requires immediate resuscitation (ACLS protocols).<br />- <strong>Stable Bradycardia</strong>: Hemodynamically stable with mild/no symptoms. Requires monitoring and assessment for reversible causes.<br /><br /><strong>Management</strong>:<br />- <strong>Unstable Bradycardia</strong>:<br />   - <strong>Medications</strong>: Atropine, dopamine, epinephrine; specific antidotes for drug toxicities.<br />   - <strong>Pacing</strong>: Transcutaneous pacing if unresponsive to medication, followed by transvenous pacing if necessary.<br />- <strong>Stable Bradycardia</strong>:<br />   - <strong>Observation</strong>: Serial ECGs, BP monitoring, correcting reversible causes including electrolyte imbalances and medication toxicity.<br />   - <strong>Specific Antidotes</strong>: Address specific drug toxicities with appropriate antidotes like glucagon or calcium gluconate.<br /><br /><strong>Clinical Pearls</strong>:<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