What to do for a patient with dizziness and bradycardia on lisinopril for controlled Hypertension (HTN)?

Management of Dizziness and Bradycardia in a Patient on Lisinopril for Hypertension

Immediate Assessment and Action

Hold the lisinopril immediately and evaluate for symptomatic bradycardia requiring urgent intervention. 1

The first priority is determining whether this bradycardia is causing hemodynamic compromise. Check for:

• Signs of hypoperfusion: altered mental status, chest discomfort, acute heart failure symptoms, oliguria, cool extremities 1, 2
• Blood pressure measurement: systolic BP <100 mmHg with symptoms indicates need for immediate intervention 3, 2
• 12-lead ECG: rule out high-degree AV block (second or third-degree), which would require different management 1, 4

Understanding the Clinical Context

While lisinopril alone rarely causes bradycardia directly 5, 6, several mechanisms may be contributing:

• Medication interactions: Lisinopril can potentiate bradycardia when combined with other rate-lowering agents, though the patient is only on lisinopril 5 mg 7
• Hypertension with left ventricular hypertrophy (LVH): The association of LVH with bradyarrhythmias, including sick sinus syndrome, has been observed in hypertensive patients 1
• Sleep-disordered breathing: Both sinus node dysfunction and AV conduction disturbances may occur in hypertensive patients with sleep apnea, where electrophysiologic properties are normal while awake 1

Acute Management Protocol

If Hemodynamically Unstable (Symptomatic Bradycardia)

Administer atropine 0.5 mg IV every 3-5 minutes (maximum 3 mg total) as first-line therapy while arranging for definitive management. 1, 3

• Monitor continuously for response: target heart rate >50-60 bpm with resolution of symptoms 3
• If atropine fails, consider epinephrine (2-10 µg/min) or dopamine (2-10 µg/kg/min) 1
• Transcutaneous pacing may be considered when full-dose atropine fails, though it may not be more effective than second-line drug therapy 1

If Hemodynamically Stable (Asymptomatic Bradycardia)

Continue holding lisinopril and observe closely with serial vital signs every 4-6 hours initially. 4

• Bradycardia <60 bpm without symptoms generally requires no immediate treatment 4
• However, if heart rate falls below 40 bpm, even in asymptomatic patients, closer monitoring is warranted 4

Diagnostic Workup

Obtain the following to identify underlying causes:

• ECG with rhythm strip: Document bradycardia type (sinus bradycardia vs. AV block) and assess for conduction abnormalities 1, 4
• Electrolytes: Check potassium (lisinopril can cause hyperkalemia in 2.2% of hypertensive patients), sodium, and renal function 5
• Thyroid function (TSH): Rule out hypothyroidism as alternative cause 2
• Sleep study consideration: Screen for obstructive sleep apnea, particularly if patient has risk factors (obesity, snoring, daytime somnolence), as this is a reversible cause of bradycardia in hypertensive patients 1

Long-Term Management Strategy

Restarting Antihypertensive Therapy

Once bradycardia resolves and blood pressure remains controlled, lisinopril can typically be restarted at the same dose (5 mg daily). 5, 6

• Lisinopril 5 mg is a low dose with good tolerability profile 5, 6
• Monitor heart rate and blood pressure at 1-2 week follow-up 3
• Target blood pressure <130/80 mmHg per current guidelines 3

If Bradycardia Persists or Recurs

Consider alternative antihypertensive agents that do not affect heart rate:

• Amlodipine or other dihydropyridine calcium channel blockers: Do not cause bradycardia and combine well with ACE inhibitors 1
• Continue ACE inhibitor therapy: ACE inhibitors do not cause bradycardia and provide mortality benefit 2
• Avoid non-dihydropyridine calcium channel blockers (diltiazem, verapamil): Risk of bradycardia and AV block, particularly when combined with beta-blockers 1

If Underlying Conduction Disease is Identified

Treat the primary cause:

• Obstructive sleep apnea: Continuous positive airway pressure (CPAP) can reverse bradyarrhythmias and reduce blood pressure 1
• Symptomatic sick sinus syndrome or high-degree AV block: May require permanent pacemaker implantation, particularly in hypertensive patients with LVH 1

Critical Pitfalls to Avoid

• Do not assume dizziness is solely from hypotension: Symptomatic bradycardia can cause cerebral hypoperfusion with dizziness even with normal blood pressure 1
• Do not restart lisinopril if bradycardia persists: Wait for heart rate to consistently exceed 55-60 bpm 2
• Do not add beta-blockers or non-dihydropyridine calcium channel blockers: These will worsen bradycardia 1
• Do not ignore sleep apnea screening: This is a common, reversible cause of bradycardia in hypertensive patients that also improves blood pressure control 1

Monitoring Parameters

Schedule follow-up within 1-2 weeks to assess:

• Heart rate and blood pressure response 3
• Resolution of dizziness symptoms 1
• Blood pressure control (target <130/80 mmHg) 3
• Development of any new symptoms suggesting worsening conduction disease 1