Block A - Medicine - Cardiology Teaching Clinic - Dyspnea

Question 1

Ddx cardiovascular causes of chronic dyspnea

Answer 1

Myocardial:

• Cardiomyopathies: HCM, RCM, DCM
• CAD
• Hypertensive heart disease

Valvular:
- AV/ MV diseases mainly

Pericardial:

• Constrictive pericarditis
• Pericardial effusion

Pulmonary vascular:

• Pulmonary thromboembolism
• PHTN

Congenital:
- Cyanotic heart diseases

Question 2

Differentiate Cardiac vs Respiratory dyspnea
- Duration, symptoms, characteristic features, signs

Answer 2

Question 3

List investigations for cardiovascular and respiratory dyspnea

Answer 3

Cardiovascular:

1. electrocardiogram (ECG),
2. chest x-ray (CXR),
3. BNP,
4. ECHO,
5. Stress testing,
6. Cardiac catheterization,
7. MRI, CT angiogram

Respiratory: Lung function test, Cardiopulmonary exercise tests

Question 4

Endocrine causes of chronic dyspnea

Answer 4

1. anaemia,
2. thyrotoxicosis,
3. metabolic acidosis,
4. deconditioning (weak muscle)

Question 5

First-line investigation for suspected cardiac dyspnea

Answer 5

Cardiac:
electrocardiogram (ECG), chest x-ray (CXR), BNP (brain natriuretic hormone), ECHO

Rule out metabolic causes:
o pH, HCO3 - metabolic acidosis
o Complete blood count - anaemia
o Thyroid-stimulating hormone - thyrotoxicosis
o Urine for protein, blood, glucose, microscopic urinalysis
o Serum K, Ca, PO4, creatinine, urea, fasting glucose - muscle weakness/ deconditioning

Question 6

P/E and first-line investigations to ddx ankle swelling

Answer 6

1. Increased hydrostatic pressure in veins: right heart failure, renal ultrafiltration failure - Elevated JVP
2. Decreased oncotic pressure due to low albumin: nephrotic syndrome (proteinuria), chronic liver disease, protein-losing enteropathy, malnutrition, sepsis (consumption of albumin)

• JVP not elevated
• look for stigmata of chronic liver disease, urine dipstick for proteinuria, any diarrhea (stool for alpha1-antitrypsin)

3. Increase in permeability: immobility, check CCB/ nitrate use

Question 7

Interpret the following PE:

BP 110/70, regular pulse 105bpm, pulsus alternans

JVP 6cm, bilateral ankle edema

CVS:
 Displaced apex to 6th ICS and mid-axillary line
 Third heart sound

 Pansystolic murmur 4/6 over apex and radiate to axilla

 Chest: bilateral basal crepitation

 Abdomen: hepatomegaly

Answer 7

Question 8

Myocarditis

• Causative pathogens

Answer 8

 Northern American and Europe: Adeno, Echo, and Coxsackie Virus
 Rest of the World: Trypanosoma Cruzi (Changas Disease) & Corynebacterium diptheriae (Diphtheria)

Question 9

Pathogenesis of myocarditis

Answer 9

Acute phase: direct infiltration of cardiotropic virus into myocytes

Subacute phase: host attempts to clear the virus:
 Natural killer cells, macrophages, and lymphoctes infiltrate infected heart tissue
 Subsequent pro-inflammatory cytokine release, NO production, antibody
secretion, upregulation of MHC

Chronic myocarditis: dilated heart with fibrosis

Question 10

First line investigations for myocarditis

Answer 10

 History: recent flu-like syndrome accompanied by fever, arthralgia, and malaise
 Laboratory tests: leukocytosis, high ESR, elevated cardiac enzyme
 ECG: ventricular arrhythmias or heart block, or mimic AMI or pericarditis
 Autoimmune marker/viral serology
 Echocardiogram/ MRI
 Cardiac catheterization: to rule out CAD
 Endomyocardial biopsy: gold standard

Question 11

Treatment for myocarditis

Answer 11

 Supportive care

 Long-term therapy for HF: ACEI, ARB, BB, diuretic, spironolactone

 Severe HF: IV inotropic therapy / implantation of ventricular assist device, heart transplantation

 Autoimmune diseases related or giant cell myocarditis:
immunosuppression therapy

Question 12

DDx Palpitation with irregular and fast heart beats

Answer 12

Tachyarrhythmia (irregularly irregular)*:
 Atrial fibrillation
 Atrial flutter with variable block
 Multifocal atrial tachycardia (usually in elderly with COPD exacerbation, pediatrics)

 Hyperthyroidism

Question 13

Interpret the following PE

o BP 95/65

o Irregularly irregular pulse 120 bpm
o JVP 7cm with giant V wave, bilateral
ankle edema

CVS:
 Tapping, non-displaced apex beat

 Right parasternal heave

 Prominent first and second heart sound with mid diastolic murmur 3/6 over left sternal border

 Chest: bilateral basal crepitation

Abdomen: pulsatile liver (3 cm below the costal margin)

Answer 13

Question 14

First-line investigations for mitral stenosis

Answer 14

CXR shows heart failure: Increase CT ratio, Upper lobe diversion, Kerley B lines

Blood tests: CBP, RFT, LFT, TFT

Echocardiogram: Hockey stick appearance of anterior leaflet – LA
dilatation; RV dilatation, thickening and stenosis of mitral valve (“fish-
mouth” thickening)

ECG: Prolonged P wave

Question 15

Interpret the following PE

o BP 100/70, regular pulse 90 bpm
o JVP 5cm, mild bilateral ankle edema
o CVS:
 Apex beat not displaced
 Right parasternal heave +ve
 Slightly prominent second heart sound
 Pansystolic murmur 3/6 over left sternal border
 Chest: clear

o Abdomen: hepatomegaly

Answer 15

Question 16

Echocardiogram:
 RA enlargement; RVH, impaired RV function (RV strain)
 Normal left ventricular function
 Flattening of interventricular septum
 Moderate tricuspid regurgitation with an estimated pulmonary artery systolic pressure of 70mmHg
 No evidence of intracardiac shunt

Possible Ddx

Answer 16

 Pulmonary arterial hypertension
 Pulmonary embolism
 Cor pulmonale
 Congenital heart disease with Eisenmenger Syndrome

Question 17

4 types of Pulmonary arterial hypertension (PAH)

Answer 17

1. Pulmonary arterial hypertension (PAH)
2. Pulmonary hypertension with left heart disease (pulmonary venous hypertension)
3. Pulmonary hypertension associated with lung diseases and/or hypoxemia
4. Pulmonary hypertension because of chronic thrombotic and/or embolic disease

Question 18

First line investigations for pulmonary hypertension

Answer 18

 ECG: RVH, right axis deviation, right atrial enlargement
 CXR: enlarge main and hilar pulmonary arterial shadows with attenuation of pulmonary arterial vascular marking
 Echocardiogram: RA and RV enlargement, TR and pulmonary arterial pressure
 Pulmonary function test
 Blood tests: serology (for connective tissue diseases) and TFT
 V/Q scan, CT/MRI and pulmonary angiography
 Right heart catheterization

Question 19

Treatment of pulmonary hypertension

Answer 19

General measures:
o Avoid exertion (lack of preload to left heart), high salt intake and pregnancy, smoking, medications (decongestant (causes vasoconstriction)

Anticoagulation

Treatment of RV failure: diuretic, digoxin and oxygen

Specific pharmacological therapies:

1. Calcium channel blocker
2. Prostanoids
3. Endothelin receptor antagonists – Bosentan
4. Phosphodiesterase-5 inhibitors – sildenafil

Non-pharmacological therapies:

1. Atrial septostomy
2. Lung transplantation