Friday 20 June 2014

Clinical Approach to Central Chest Pain

Clinical approach to “Central” Chest Pain

Clinical approach to “Central” Chest Pain

Differential diagnosis

  • Esophageal pain
    • Esophageal spasm
    • Esophageal reflux
  • Musculoskeletal pain
  • Anginal pain

History taking

  • Active process.
  • Direct questioning to check details and to confirm common understanding of the words.
  • Co-existing fundamentally different pain is also possible.

Characteristics of Angina “like” central chest pain

Site

  • Constant and characteristic for each patient (different for different patients).
  • Location is diffuse.
  • Not “inframammary”.

Character

  • Gripping/tight.
  • Not stabbing/sharp.

Severity

  • Unrelated to severity/duration of ischemia.
  • Silent ischemia: 50% of times.

Onset

  • Not abrupt.
  • Pain is either present or absent. It is not a background pain.

Duration and relief

  • Ischemia: 3-10 mins. Decreases with relaxation/rest/nitrates (Onset of action: 2-3 mins).
  • Infarction: pain > 30 mins. Any pain more than 30 mins without any subsequent evidence of myocardial infarction (Clinical, ECG, cardiac enzymes) - CARDIAC INVOLVEMENT UNLIKELY.

Initiation factor

  • Stable effort angina:

    • Atherosclerotic plaque (leading to fixed coronary artery narrowing)
      • At rest and upto certain limit of effort: normal blood supply distally.
      • After certain limit: blood supply to distal region impaired, “angina” develops.
    • Precipitated by: physical exertion, emotional stress, excessive meals, cold weather.
    • Stereotype events: Rest (asymptomatic) –> Exertion (asymptomatic) –> more exertion (angina) –> Rest (asymptomatic)
  • Unstable angina/acute myocardial infarction:

    • Plaque fissure
      • Thrombus –> intraluminal extension (Fixed component)
      • Chemical mediators –> VAsospasm (Dynamic component)
    • Stereotype is lost
      • Angina: unexpected occurence, increased frequency and duration.
    • Different cases have different proportion of:
      • THROMBUS ——— VASOSPASM (100% is called prinzmetal angina)
  • Symdrome X (Microvascular syndrome):

    • Indistinguishable from Stable Effort Angina.

Confirmation of diagnosis

  • Stress Angina:
    • Stress Testing: proves that chest pain is due to cardiac cause.
    • Angiography: diagnosis of cause as coronary block.
  • Unstable Angina:
    • Stress Testing: Potentially dangerous.
    • Continuous ECG monitoring.
  • Syndrome X:
    • Stress Testing: positive.
    • Angiography: negative.

Cardiac vs esophageal pain

  • Chest pain > 30 min and ECG normal: Unlikely to be cardiac.
  • Chest pain decreasing with antacids: Esophageal.
  • Chest pain increased with deglutition of saliva: Esophageal.
  • Chest pain associated with dysphagia: Esophageal.

May be indistinguishable

Cardiac vs muscular pain

  • Chest pain induced by movement of part: Muscular pain.

Chest Radiograph: Cardiac Perspective

Chest Radiograph

Chest Radiograph

  • Congenital heart disease: Abnormal
  • Acquired heart disease: Usually Normal

PA view

  • Patient upright and breath held in full end inspiration.

Heart size

  • AP > PA view (as heart further from film in AP view).

Normal Chest Radiograph

Cardiac silhoutte (PA view)

CXR PA view

Cardiac silhoutte (Lateral view)

CXR Lateral view

Pulmonary vasculature

Pulmonary vasculature

Heart size

  • Transverse cardiac diameter: \( \leq \) 16 cm in males and \( \leq \) 15 cm in females.
  • Cardiothoracic ratio: \( \leq \) 50%.

Analysis of Chest Radiograph

  • Cardiac shadow: ANATOMIC ASPECT.
  • Pulmonary vasculature: PHYSIOLOGIC ASPECT.
  • ORDER OF ANALYSIS
    • Technical consideration
      • Overexposed: Pulmonary oligemia.
      • Underexposed: Increased pulmonary vasculature.
      • In expiration: Diffuse lung disease.
      • Rotated film: Abnormal heart size.
    • Skeletal system
      • Pectus excavatum: Straightening of left heart border.
      • Straight back syndrome: Cardiomegaly.
      • Scoliosis.
      • Sternal depression & straight back syndrome: Associated with MVP.
      • Down syndrome: 11 pair of ribs & VSD.
      • Rib notching: Coarctation of aorta, pulmonary atresia, vena caval syndrome, Blalock Taussig Shunt.
    • Upper abdomen
      • Gall stones, histus hernia in chest pain.
      • Situs.
    • Lungs
    • Cardiac shadow

Lungs

  • Look for co-existing lung diseases.
  • Pulmonary vasculature
    • Increased
      • Pulmonary venous hypertension (PVH), PAH, pulmonary over-circulation.
    • Decreased
      • Oligemia.
    • Normal
      • DOESNOT EXCLUDE SIGNIFICANT MYOCARDIAL DISEASE, MILD VALVULAR DISEASE OR SMALL INTRA-CARDIAC SHUNT.
    • Uneven

Abnormalities of Pulmonary circulation

  1. Pulmonary venous hypertension (Close correlation exists between PCWP and extent of PVH in untreated patients)
    • Stage 1 (< 12 mmHg)
      • Normal findings.
    • Stage 2 (12 - 18 mmHg)
      • Pulmonary vein dilation. D/D: Basal emphysema.
        • Upper lobe diversion.
    • Stage 3 (18 - 22 mmHg)
      • Interstitial edema. D/D: Non Cardiogenic Pulmonary Edema.
        • Perihilar haze.
        • Peribronchial cuffing.
        • Kerley B lines - Interlobular edema.
        • Kerley A lines - Thickened inter lobular septum.
    • Stage 4 (> 22 mmHg)
      • Alveolar edema. D/D: Non Cardiogenic Pulmonary Edema.
        • Perihilar.
        • Can be patchy/asymmetrical.
        • Pleural effusion.
    • Chronic PVH (Causes)
      • PAH.
      • Pulmonary hemosiderosis (bileteral, diffuse, granular).
      • Pulmonary ossicles (Calcified, basal, nodules upto 1 cm).
  2. Pulmonary arterial hypertension (PAH)
    • Definition: PAsysP > 30 mmHg.
    • Features:
      • Central PA increased (D/D: Hilar lymphadenopathy - lymphadenopathy is more lobular).
      • Peripheral PA decreased.
      • Calcification of central PA.
  3. Pulmonary over-circulation
    • Pulmonary:systemic circulation < 2:1
      • No changes.
    • Pulmonary:systemic circulation \( \geq \) 2:1
      • Central PA increased.
      • Peripheral PA increased (extending > lateral 1/3rd of lung field).
      • LOOK FOR CYANOSIS:
        • Present: Bidirectional shunt.
        • Absent: Left to right shunt.
  4. Bronchial circulation
    • Severe RV outflow obstruction.
  5. Pulmonary oligemia
    • TOF.
    • Cardiac tamponade (Restricted filling of RV).
  6. Uneven vascularity
    • Pulmonary disease (Commonest cause).
    • Cardiogenic causes
      • Pulmonary thrombo-embolism.
      • Shunt surgery.
      • Pulmonary arterial stenosis.
      • Pulmonary AV fistula.

Cardiac shadow

  1. Systemic veins
    • SVC
      • Increased flow: Supra-cardiac anomalous pulmonary vein return.
      • Increased pressure: Rt HF, Tricuspid valvular disease, Cardiac tamponade, Constrictive pericarditis.
      • Obstruction: Mediastinitis, Mediastinal tumor.
    • Azygous vein
      • IVC obstruction.
    • IVC
      • Rt HF.
      • TR/TS.
  2. Right atrium dilation
    • Increased prominence of lower half of right heart border.
  3. Right ventricle dilation
    • PA view
      • Apex outwards and upwards.
      • Gross dilation: forms Lt heart border and bump just below pulmonary trunk.
    • Lateral view
      • Decreased retro-sternal space.
    • Pulmonary trunk
      • Increased
        • PAH: associated peripheral pruning.
        • Pulmonary over-circulation: associated pulmonary plethora.
        • Post stenotic/idiopathic: associated normal pulmonary vasculature.
      • Decreased
        • TOF.
        • Pulmonary atresia.
      • Absent
        • Corrected transposition of Great Vessels.
  4. Left atrium dilation
    • Increased carinal angle.
    • Right sided double density (marked dilation: can form right border).
    • Denting of esophagus (Lateral view, Barium swallow).
    • Straightening/convexity of left atrial appendage.
  5. Left ventricle
    • Hypertrophy
      • Increased Lt heart border convexity.
    • Dilatation
      • PA: Apex outwards and downwards, increased cardio-thoracic ratio.
  6. Aorta
    • Increased Ascending Aorta
      • Post-stenotic dilation.
      • Aneurysm.
    • Increased Aortic Knuckle
      • Aneurysm.
      • PDA.
      • Pulmonary atresia.
    • Increased Descending Aorta
      • Aneurysm.
    • Increased Thoracic Aorta
      • Systemic hypertension.
      • Aortic regurgitation.
  7. Pericardium
    • Pericardial effusion
      • Non-specific globular enlargement.
      • Normal pulmonary vasculature.
    • Congenital absence of pericardium
      • Left displacement of cardiac shadow.
  8. Cardiac calcification
    • Fluoroscopy better than Plain Films.
    • VALVE CALCIFICATION
      • Aortic valve
        • PA view: over spine (may be obscured)
        • Lateral view: (see figure)
      • Mitral valve
        • PA view: Lt side of spine
        • Lateral: (see figure)