Question 23

You are asked to review a 75-year-old man who has developed sudden onset hypotension, with a systolic BP of 70mmHg and an associated sinus tachycardia of 140 bpm, 30 minutes post TAVR (transcatheter aortic valve replacement) via the trans-femoral approach.
a) List four cardiac differential diagnoses of hypotension. (20% marks)
b) List four non-cardiac differential diagnoses of hypotension. (20% marks)
c) Explain which features on history, clinical examination, and investigations, may help differentiate cardiac from non-cardiac causes? (60% marks)

[Click here to toggle visibility of the answers]

College answer

Aim: To explore the complications of a common cardiology procedure.
Key sources include: Common cardiology procedure seen in clinical practice. CanMEDS Medical Expert.
Discussion: This topic was generally well addressed by candidates with the non-cardiac causes of hypotension e.g., femoral access retroperitoneal bleed or anaphylaxis, well recognised. Candidates would have improved their answers if they gave cardiac differentials specific to the clinical case provided outlining post-TAVR instability. For example, a discussion around severe AR/paravalvular leak from TAVR malposition or ventricular perforation/aortic root rupture related tamponade would have allowed the candidate to demonstrate competency with the assessment of the post TAVR unstable patient and improve their answer in part a and c.

Discussion

Unstable arrhythmia (AF, SVT, VT)
Aortic annular rupture or aortic root rupture
Paravalvular aortic regurgitation
Displacement of the TAVI device
Iatrogenic ventricular septal defect
Fistula from the left ventricle to the atria (iatrogenic Gerbode defect)
Perforation of the anterior mitral valve curtain
Acute coronary artery occlusion
Cardiac tamponade
LV outflow tract obstruction ("left ventricular suicide")

Retroperitoneal bleed from the femoral access
Cardiotoxic effects of anaesthetic agents
Sepsis due to undeclared perioperative infection
Bowel ischaemia due to atheromatous emboli
Anaphylaxis
Post-TAVR autodiuresis

History, to look for
- Anaphylaxis (allergy list and medication chart)
- Drug error ("did you seriously give 100mg IV metoprolol")
- Procedural complications
Physical examination looking for:
- Conduction disturbance
  - Pulse rate
  - Arrhythmia
- Aortic pathology
  - Radioradial and radiofemoral delay
  - Murmur
- Tamponade
  - Pulse pressure variation, pulsus paradoxus
  - CVP trend
  - Neck veins (distended?)
  - Heart sounds (muffled?)
- Bleeding
  - Pallor
  - Abdominal distension
  - Brusing or swelling of the arterial puncture sites
  - Pulses in the distal limbs (occluded by haematoma?)
Bedside tests
- ECG, looking for arrhythmias and conduction blocks
- TTE/TOE, looking for paravalvular leak and other cardiac/valvular injury, and of course for effusion and tamponade
- TOE can also assess for aortic dissection in a limited way
Biochemistry
- ABG, to immediately assess lactate and haemoglobin (as well as any electrolyte abnormalities that might be contributing to a conduction disturbance or arrrhythmia)
- FBC, in case
- ACT or TEG to find any coagulopathy
Imaging
- CXR looking for mediastinal widening and TAVR device embolisation
- CT aortogram and CT abdomen, to exclude aortic dissection and retroperitoneal haematoma

References

Agnihotri, Arvind. "2012 ACCF/AATS/SCAI/STS expert consensus document on transcatheter aortic valve replacement: Executive summary." The Journal of Thoracic and Cardiovascular Surgery 144.3 (2012): 534-537.

Raiten, Jesse M., et al. "Critical care management of patients following transcatheter aortic valve replacement." F1000Research 2 (2013).

Clegg, Stacey D., and Mori J. Krantz. "Transcatheter aortic valve replacement: what's in a name?." Journal of the American College of Cardiology 60.3 (2012): 239-239.

Thiele, Holger, et al. "General versus local anesthesia with conscious sedation in transcatheter aortic valve implantation: the randomized SOLVE-TAVI trial." Circulation 142.15 (2020): 1437-1447.

Klinkhammer, Brent J., Cornelius M. Dyke, and Thomas A. Haldis. "The development or worsening of hypertension after transcatheter aortic valve replacement (TAVR) improves short-term and long-term patient outcomes." Heart Asia 10.2 (2018).

Lindman, Brian R., et al. "Lower blood pressure after transcatheter or surgical aortic valve replacement is associated with increased mortality." Journal of the American Heart Association 8.21 (2019): e014020.

Tomey, Matthew I., Umesh K. Gidwani, and Samin K. Sharma. "Cardiac critical care after transcatheter aortic valve replacement." Cardiology Clinics 31.4 (2013): 607-618.

Suh, William M., Christian F. Witzke, and Igor F. Palacios. "Suicide left ventricle following transcatheter aortic valve implantation." Catheterization and Cardiovascular Interventions 76.4 (2010): 616-620.

[Submit a comment or correction]