How to manage a patient with hypertension and dizziness, with a history of triple bypass surgery?

Management of Hypertension and Dizziness in a Post-CABG Patient

This patient requires urgent MRI brain imaging to exclude hypertensive encephalopathy, posterior reversible encephalopathy syndrome (PRES), or acute stroke, as dizziness/unsteadiness in the setting of stage 2 hypertension represents a neurological symptom that significantly increases the likelihood of intracranial pathology requiring immediate identification. 1

Immediate Diagnostic Workup

Neuroimaging is the priority because dizziness represents impaired cerebral autoregulation in severe hypertension and may indicate evolving hypertensive encephalopathy or acute cerebrovascular pathology. 1, 2 The presence of neurological symptoms—not the absolute blood pressure value—defines whether this is a hypertensive emergency requiring immediate intervention. 1

Critical Laboratory and Diagnostic Studies

Complete the following immediately:

• Laboratory analysis: Hemoglobin, platelet count, creatinine, sodium, potassium, LDH, haptoglobin, quantitative urinalysis for protein, and urine sediment 1
• ECG and fundoscopy to assess for other manifestations of acute hypertension-mediated organ damage (HMOD) 1
• MRI brain (preferred over CT) to identify hypertensive encephalopathy, PRES, or stroke 1

Common Pitfall to Avoid

Do not dismiss the dizziness as "benign" or delay imaging while attempting blood pressure reduction. 1 Even when the formal neurological examination appears normal, unsteadiness significantly increases the odds of finding abnormalities on neuroimaging. 1 The absence of focal deficits on exam does not exclude hypertensive encephalopathy, PRES, or early stroke. 1

Blood Pressure Management Strategy

If Imaging Confirms Hypertensive Emergency (Encephalopathy/PRES/Stroke)

Initiate immediate intravenous antihypertensive therapy in an intensive care setting. 1 The target is to reduce mean arterial pressure (MAP) by 20-25% over the first hour, then to 160/110-100 mmHg over the next 2-6 hours. 1

Appropriate IV agents include:

• Nicardipine
• Labetalol
• Sodium nitroprusside 3

Nitroglycerin is the agent of choice if there is concurrent coronary ischemia given this patient's history of triple bypass. 3

If Imaging is Negative (Hypertensive Urgency)

The blood pressure of 162/92 mmHg does not require emergency IV treatment if no acute organ damage is present. 3 However, given the patient's cardiac history:

• Continue existing antihypertensive medications if the patient is already on therapy 3
• Avoid rapid blood pressure reduction as this can precipitate ischemia in patients with coronary artery disease 3
• For stage 2 hypertension (≥160/100 mmHg), cautiously reduce BP by no more than 10-20% and observe for neurological deterioration 3

Special Considerations for Post-CABG Patients

This patient's history of triple bypass surgery creates specific management considerations:

Perioperative Context (If Recent Surgery)

• Beta-blockers should be continued if the patient was taking them pre-operatively, as abrupt cessation can cause rebound hypertension 4
• ACE inhibitors/ARBs can be resumed as soon as clinically feasible post-operatively 3
• Postoperative hypertension is common due to increased sympathetic tone, pain, and increased intravascular volume 3

Cardiac Ischemia Risk

Monitor closely for myocardial ischemia as uncontrolled hypertension increases the risk for perioperative ischemic events in patients with coronary artery disease. 3 The borderline T-wave abnormalities on ECG warrant particular attention.

Dizziness Evaluation Algorithm

While awaiting imaging, assess the timing and triggers of dizziness rather than relying on symptom quality alone: 5

Three Key Categories:

1. Acute vestibular syndrome (constant dizziness for days): Consider vestibular neuritis vs. stroke—requires HINTS examination if peripheral vertigo suspected 5

2. Spontaneous episodic (comes and goes without trigger): Consider vestibular migraine vs. TIA 5

3. Triggered episodic (positional): Consider benign paroxysmal positional vertigo—perform Dix-Hallpike maneuver 6, 5

This patient's constant 3-day duration suggests acute vestibular syndrome, making stroke differentiation critical. 5

Physical Examination Priorities

• Orthostatic blood pressure measurement to exclude orthostatic hypotension from medications 7, 6
• Full neurologic examination focusing on focal deficits 7
• Assessment for nystagmus and its characteristics 6
• HINTS examination (head-impulse, nystagmus, test of skew) if peripheral vertigo is suspected to distinguish from central causes 6, 5

Management Algorithm Summary

1. Obtain MRI brain immediately 1
2. Complete laboratory workup and ECG 1
3. If hypertensive emergency confirmed: IV antihypertensives in ICU, target MAP reduction 20-25% over 1 hour 1
4. If hypertensive urgency: Cautious oral BP management, avoid rapid reduction 3
5. Continue cardiac medications (beta-blockers, ACE inhibitors) unless contraindicated 3, 4
6. Monitor for cardiac ischemia given CABG history and ECG abnormalities 3

The rate of BP rise and presence of organ damage—not the absolute BP number—determines urgency of treatment. 2 Patients with chronic hypertension often tolerate higher pressures than previously normotensive individuals. 2