FU(11): Abnormalities of Conduction & pHTN

Question 1

In a patient with pulmonary arterial hypertension (PAH), which factor is most crucial to maintain during anesthesia?

Answer 1

Maintain RV preload and reduce RV afterload

Question 2

In a patient with pulmonary hypertension, what is the most significant risk associated with general anesthesia?

Answer 2

RV failure

Question 3

A patient with poorly controlled hypertension is undergoing a major abdominal surgery. Which intraoperative complication is this patient most at risk for?

Answer 3

Myocardial ischemia

Question 4

A patient with a history of pulmonary arterial hypertension (PAH) is scheduled for non-cardiac surgery. Which of the following is the most appropriate perioperative management?

Answer 4

Maintenance of normocarbia

Question 5

A patient with a history of pulmonary arterial hypertension (PAH) is scheduled for elective surgery. Which anesthetic technique is most appropriate?

Answer 5

TIVA

Question 6

During surgery, a patient with a history of pulmonary arterial hypertension (PAH) and right ventricular (RV) failure develops acute hypotension. What is the most appropriate immediate intervention?

Answer 6

Initiate nitric oxide therapy
If due to decrease SVR → vasopressor
If due to RV failure → iNO or iloprost

Question 7

A patient with systemic hypertension and left ventricular hypertrophy (LVH) is undergoing major surgery. Which of the following is the primary concern regarding anesthesia management?

Answer 7

Risk of hypotension and decreased coronary perfusion

Question 8

A 65-year-old male with a history of systemic hypertension is scheduled for elective surgery. Preoperative assessment reveals well-controlled blood pressure with ACE inhibitors. During surgery, the patient exhibits significant intraoperative blood pressure variability. What is the most likely underlying pathophysiological mechanism for this intraoperative hemodynamic instability?

Answer 8

Reduced baroreceptor sensitivity d/t chronic HTN

Question 9

A patient with a history of pulmonary arterial hypertension (PAH) is undergoing non-cardiac surgery. Which of the following anesthetic considerations is most critical due to the pathophysiology of PAH?

Answer 9

Strict maintenance of normocarbia to avoid hypoxic pulmonary vasoconstriction

Question 10

Deleted: A 55-year-old patient with a history of myocardial infarction is undergoing elective surgery. During anesthesia, the ECG shows a new onset of Left Bundle Branch Block (LBBB). Which of the following is the most likely cause of this finding?

Answer 10

Myocardial ischemia

Question 11

A patient presents with symptomatic bradycardia. ECG shows a regular rhythm with a heart rate of 45 bpm and a narrow QRS complex. Which of the following is the most likely diagnosis?

Answer 11

junctional (no p waves)

Question 12

A patient with chronic renal failure undergoing surgery exhibits a prolonged QT interval. Which drug should be used with caution?

Answer 12

amio

Question 13

A patient with Wolff-Parkinson-White (WPW) syndrome develops a tachyarrhythmia. Which of the following drugs is contraindicated?

Answer 13

dig

Question 14

In a patient with a history of myocardial infarction, which ECG finding would most strongly suggest ischemia?

Answer 14

ST elevation

Question 15

In a patient with Wolff-Parkinson-White Syndrome, what ECG finding is typically observed?

Answer 15

delta wave

Question 16

What is the primary mechanism of arrhythmia in Torsades de Pointes?

Answer 16

triggered activity

Question 17

A patient with an inferior myocardial infarction is at increased risk for which of the following conduction disturbances?

Answer 17

AV block
Inferior wall MI (occlusion of the RCA) p/w bradyarrhythmias or heart block. Slower ectopic foci take over rate dominance due to the ischemic insult and dysfunction of AV and SA nodes

Question 18

A 55-year-old patient presents with signs of myocardial ischemia. An ECG shows ST elevation in leads II, III, and aVF. What is the most likely cause?

Answer 18

Inferior wall MI (RCA)

Question 19

A 65-year-old patient with a history of hypertension and diabetes is scheduled for elective surgery. Preoperative ECG shows a left bundle branch block (LBBB). During the operation, you notice ST-segment elevation in leads V1 to V3. What is the most likely cause of this ECG finding?

Answer 19

Normal variant due to pre-existing LBBB

Question 20

During a complex cardiothoracic surgery, a patient with a history of ischemic heart disease and recent myocardial infarction (MI) suddenly develops a new left bundle branch block (LBBB) on the intraoperative ECG, accompanied by hypotension and tachypnea. What is the most appropriate initial management step?

Answer 20

Urgent echocardiographic assessment

Question 21

A patient undergoing a neurosurgical procedure with a history of Brugada syndrome exhibits wide-complex tachycardia resembling ventricular tachycardia (VT), but remains asymptomatic and hemodynamically stable. What is the most appropriate management strategy?

Answer 21

Administration of IV procainamide

Question 22

During a high-risk cardiac surgery, a patient with known hypertrophic cardiomyopathy (HCM) and recurrent nonsustained ventricular tachycardia (NSVT) suddenly develops sustained ventricular tachycardia (VT) with hemodynamic instability. The patient is already on appropriate beta-blocker therapy. What is the most appropriate immediate management step?

Answer 22

Unstable VT w/ pulse = synchronized cardioversion

Unstable VT w/o pulse = defib

Question 23

A 55-year-old male with a history of obesity and chronic stress presents with a blood pressure of 155/95 mm Hg. He has a strong family history of hypertension. His physical examination is notable for bilateral carotid bruits and a BMI of 32 kg/m^2. Laboratory studies show no evidence of secondary causes of hypertension. How does chronic sympathetic nervous system overactivity contribute to this patient’s primary hypertension?

Answer 23

It increases renal Na and H2O reabsorption leading to volume expansion

Question 24

A 60-year-old female is diagnosed with primary hypertension. She has a moderate intake of dietary sodium and a sedentary lifestyle. Her blood work indicates increased levels of plasma renin activity. What role does dysregulation of the renin-angiotensin-aldosterone system play in the pathogenesis of this patient’s hypertension?

Answer 24

Activation of angiotensin 2 leads to vasoconstriction and Na retention

Dysregulated renin release causes elevated renin levels → increased AT2 & aldosterone release → HTN

Question 25

A 45-year-old woman with primary hypertension is noted to have impaired endothelium-dependent vasodilation. She has no history of cardiovascular disease but has high-normal cholesterol levels. What is the implication of endothelial dysfunction in the pathogenesis of this patient’s hypertension?

Answer 25

Reduced synthesis or availability of endothelium-derived vasodilators like NO

Question 26

A 58-year-old male is scheduled for elective hernia repair. He has a history of hypertension, currently controlled with a thiazide diuretic and an ACE inhibitor, which he was instructed to hold on the morning of surgery. In the preoperative area, his blood pressure is recorded at 160/100 mm Hg. Why is it generally acceptable to proceed with surgery in this patient despite preoperative blood pressure elevation?

Answer 26

Single BP reading may not accurately represent chronic BP control, and asymptomatic patients w/o end-organ damage are at low risk for periop complications from HTN

Unless SBP >180 and/or DBP >110 or end-organ injury, generally ok to proceed

Question 27

A 65-year-old female with a history of poorly controlled hypertension presents for elective cholecystectomy. Her echocardiogram shows left ventricular hypertrophy with diastolic dysfunction. Her blood pressure on the day of surgery is 178/92 mm Hg. Considering her left ventricular hypertrophy and diastolic dysfunction, why is meticulous blood pressure control important in this patient?

Answer 27

LVH decreases chamber compliance, making it sensitive to volume changes and requires careful BP management to prevent end organ ischemia

Question 28

A 32-year-old man is scheduled for outpatient arthroscopic knee surgery. He has no prior history of hypertension but presents with a preoperative blood pressure of 190/110 mm Hg and reports occasional headaches and palpitations. Why might this patient’s surgery be delayed for further evaluation of his hypertension?

Answer 28

Symptoms of severe HTN w/o prior diagnosis suggest a secondary cause, such as pheochromocytoma, which requires preop optimization to prevent intraop HTN crisis

Question 29

A 70-year-old woman with chronic hypertension controlled with an ACE inhibitor and a β-blocker is scheduled for a total hip replacement. Her preoperative blood pressure is 145/85 mm Hg. Why is the continuation of her β-blocker recommended on the day of surgery?

Answer 29

Abrupt WD of BB can lead to HTN and tachycardia which can increase perioperative CV risk

Question 30

A 62-year-old male with a history of refractory hypertension on five antihypertensive medications is undergoing vascular surgery for an aortic aneurysm. His preoperative blood pressure is controlled at 138/82 mm Hg. In managing a patient with refractory hypertension, why is it crucial to maintain a slightly elevated systemic vascular resistance intraoperatively?

Answer 30

Helps ensure adequate perfusion pressure across vital organs, considering the patient’s reduced functional reserve from chronic HTN end-organ damage
Even brief periods of hypotension are associated with AKI, MI, & death

Question 31

A 68-year-old woman with a history of chronic kidney disease and hypertension presents with a blood pressure of 210/120 mm Hg and headache but no signs of end-organ damage. She is scheduled for an urgent hysterectomy due to heavy bleeding. Why should blood pressure management be titrated slowly in this patient’s urgent hypertensive crisis without end-organ damage?

Answer 31

Titrate BP down slowly to avoid overshoot hypotension

Question 32

A patient with a known history of hypertension presents to the emergency department with a blood pressure of 220/130 mm Hg and severe chest pain radiating to his back. A CT scan confirms an acute aortic dissection. In the management of a hypertensive crisis with aortic dissection, why is the addition of a β-blocker such as esmolol to arteriolar dilator therapy particularly desirable?

Answer 32

To reduce shear stress
Aortic dissection management goal is to decrease the pulsatile force of LV contraction, which a BB can help with
B1 selective → decrease HR → decrease CO → decrease stress on aorta

Question 33

A 60-year-old patient presents with labile blood pressures, ranging from 170/100 mm Hg to 250/120 mm Hg, accompanied by episodes of severe headaches, palpitations, and diaphoresis. Biochemical testing reveals elevated catecholamine levels, and an MRI shows an adrenal mass suggestive of pheochromocytoma. Why is controlled blood pressure reduction crucial in patients with pheochromocytoma presenting with a hypertensive crisis?

Answer 33

Pt is at risk for catecholamine-induced cardiomyopathy and arrhythmias, which can be exacerbated by abrupt changes in BP
Avoid overshoot hypotension
Caution with BB as unopposed alpha-adrenergic stimulation can worsen HTN

Question 34

A patient with a history of hypertension treated with clonidine is scheduled for major abdominal surgery. Clonidine was stopped 24 hours before surgery due to concerns about perioperative hypotension. In the PACU, the patient exhibits markedly elevated blood pressure and heart rate. Why may dexmedetomidine be considered in the management of a patient with clonidine withdrawal syndrome?

Answer 34

Clonidine is an alpha 2 agonist and WD happens within 18-24h after stopping → HTN and tachycardia
Dex is a rapid-acting alpha 2 agonist

Question 35

A 55-year-old woman with PAH, characterized by a mean pulmonary artery pressure (mPAP) of 35 mm Hg and pulmonary vascular resistance (PVR) of 4 Wood Units (WU), is undergoing elective cholecystectomy. She is currently treated with an endothelin receptor antagonist. In the perioperative management of this patient with PAH, why is it crucial to maintain a stable cardiac output (CO) and avoid increases in PVR?

Answer 35

An increase in PVR or decrease in CO could exacerbate RV strain and lead to RV failure

Under normal circumstances, the RV intramyocardial pressure is lower than the aortic root pressure, and the RV coronary perfusion occurs throughout the cardiac cycle. However, owing to the elevated RV intramyocardial pressure present in PAH, more coronary flow occurs during diastole, making the RV vulnerable to systemic hypotension, which worsens the mismatch between oxygen demand and supply and can precipitate ischemia.

Question 36

A 60-year-old man with moderate PAH (mPAP of 32 mm Hg) is experiencing an intraoperative hypertensive crisis during a total hip replacement. He is on combination therapy with a PDE-5 inhibitor and an endothelin receptor antagonist. In managing this intraoperative PAH crisis, which intervention is most appropriate to prevent further pulmonary vascular constriction and potential right ventricular failure?

Answer 36

Administer IV vasodilators that selectively reduce PVR w/o significantly affecting SVR

Question 37

A 45-year-old woman with PAH is scheduled for an elective laparoscopic cholecystectomy. She is currently managed with sildenafil and periodic inhaled nitric oxide therapy. Why is maintaining a stable nitric oxide level crucial during surgery for a patient with PAH?

Answer 37

To ensure consistent pulmonary vasodilation and prevent sudden spikes in PAP

Nitric Oxide stimulates guanylate cyclase→ increased cGMP in smooth muscle→ pulmonary vasodilation. We want to keep a stable level of nitric oxide as its effect is transient. Nitric oxide is quickly bound by hemoglobin or other molecules and degraded by phosphodiesterase 5 (PDE5).
Additionally, laparoscopic surgery requires CO2 pneumoperitoneum, head-down position, and increased inspiratory pressure required for mechanical ventilation to prevent atelectasis — all affecting filling pressures and afterload (even in healthy patients).

Question 38

A 68-year-old patient with a history of PAH functional class III is scheduled for elective knee replacement surgery. The patient has been on tadalafil and is scheduled for preoperative right heart catheterization. Why is preoperative right heart catheterization crucial in this patient with PAH before knee replacement surgery?

Answer 38

Provides accurate HD data to assess the severity of PAH and guide peri-op management, including anesthesia

During joint replacements, there is a risk for embolic showers that acutely increase RV afterload. During right heart catheterizations, they perform studies with inhaled nitric oxide to determine responsiveness to vasodilator therapy and can indicate the effectiveness of Ca Channel blockers as well. Understanding this can help guide preoperative therapy to optimize their status before entering surgery. It can also guide therapy choices intraoperatively for acute RV afterload increases in the case of an embolic shower.

Question 39

A patient with PAH presents for abdominal surgery. The patient experiences dyspnea on minimal exertion and reports a decrease in exercise tolerance over the past few months. In a PAH patient with worsening exercise tolerance, what is the primary anesthesia consideration during abdominal surgery?

Answer 39

Maintain PVR and RV function to prevent intra-op and post-op decompensation

Primary goal with PAH pts is maintaining optimal “mechanical coupling” between RV and pulmonary circulation to promote adequate left-sided filling and systemic perfusion. This can be achieved by reduced PVR to reduce the workload of RV but maintain preload

Question 40

A 55-year-old patient with PAH is scheduled for a laparoscopic cholecystectomy. The patient is taking sildenafil and reports occasional chest discomfort with exertion. An echocardiogram has shown RV hypertrophy and reduced RV compliance. For the patient with PAH and RV hypertrophy undergoing laparoscopic cholecystectomy, why is careful management of intraoperative ventilatory settings essential?

Answer 40

to avoid increases in RV afterload from PPV and hypercarbia, which can lead to RV failure

Question 41

A patient with idiopathic PAH, on combination therapy including a prostanoid, is admitted for an emergency appendectomy. The patient has had a recent syncope episode and is classified as NYHA functional class III. Why is the continuation of prostanoid therapy critical in a PAH patient undergoing emergency appendectomy?

Answer 41

Prostanoids reduce PVR and inhibit platelet aggregation which is crucial for maintaining RV function during acute surgical stress

They mimic the effect of prostacyclin to produce vasodilation while inhibiting plt aggregation, anti-inflammatory effects and reduced proliferation of vascular smooth muscle cells

Question 42

A 70-year-old patient with PAH is scheduled for elective hernia repair. The patient has marked RV dilation and significant tricuspid regurgitation on echocardiography. What is the primary anesthetic concern for a patient with PAH, RV dilation, and tricuspid regurgitation during hernia repair?

Answer 42

To avoid perioperative factors that could further increase RV afterload and exacerbate TR

Question 43

A 68-year-old patient with idiopathic PAH is scheduled for a total knee arthroplasty. The patient is currently managed on oral endothelin receptor antagonists and reports shortness of breath with minimal exertion. Why should embolic phenomena be a particular concern during total knee arthroplasty in a patient with idiopathic PAH?

Answer 43

Embolic showers produced by different stages of joint replacement procedures that can acutely increase RV afterload by obstructing pulmonary vasculature

Question 44

A 59-year-old patient with moderate PAH is scheduled for laparoscopic abdominal surgery. The patient’s PAH is managed with a combination of a prostanoid and a PDE5 inhibitor. In a patient with moderate PAH undergoing laparoscopic surgery, why is the management of carbon dioxide insufflation critical?

Answer 44

CO2 insufflation can increase RV afterload and impede ventricular filling, exacerbating PAH

The required carbon dioxide pneumoperitoneum has an acute impact on biventricular load and pump function. The combination of pneumoperitoneum, head-down position, and increased inspiratory pressure required for mechanical ventilation prevention of atelectasis affects filling pressures in both the magnitude and character of afterload.
Retained carbon dioxide and hypercarbia have been linked to reductions in cardiac output and increases in pulmonary arterial pressures even when the pneumoperitoneum is relieved.

Question 45

A 73-year-old patient with severe PAH requiring continuous intravenous prostanoid therapy is undergoing a thoracoscopic lobectomy for lung cancer. For a patient with severe PAH on continuous intravenous prostanoid therapy, why is the administration of inhaled pulmonary vasodilators recommended during thoracoscopic surgery?

Answer 45

To selectively reduce PAP and limit inhibition of HPV, thereby optimizing right ventricular function

To facilitate care, patients with PAH are often converted from oral to inhaled or parenteral pulmonary vasodilator therapy. To lessen the potential for Hypoxic Pulmonary Vasoconstriction inhibition and systemic hypoxia, it has been recommended that inhaled pulmonary vasodilators be administered during single ventilation to allow for limiting or even discontinuing IV therapy for a period of time.

Question 46

A 35-year-old patient with PAH is undergoing a non-emergent cesarean section. The patient has been managed on a regimen of oral ERA and a diuretic. There is a noted NYHA functional class II status. What is the primary anesthetic consideration for a patient with PAH undergoing a cesarean section?

Answer 46

Maintain stable hemodynamics, avoiding factors to worsen PAH & maintain placenta perfusion

Maintain stable hemodynamics avoiding factors to worsen PAH, such as hypoxemia, hypercarbia, acidosis, and increased intrathoracic pressures.
spinal/epidural > general anesthesia, judicious fluid use, support cardiac output.
maintain placenta perfusion??
RV is already experiencing an increased workload due to pregnancy