Table 3 Etiology and investigation of post-cardiopulmonary bypass ventricular dysfunction

General

   Exacerbation of preoperative ventricular dysfunction with relative intolerance to cardioplegic asystolic, hypoxic arrest

TOE

Global or regional wall motion abnormality

   Reperfusion injury

TOE

Global wall motion abnormality

   Inadequate myocardial protection (underlying coronary anatomy, route of cardioplegia, type of cardioplegia)

TOE

Global wall motion abnormality

Case/patient specific

   Ischaemia/infarction

Vessel spasm (native coronaries, internal mammary artery)

ECG, TOE, graft flow

ECG changes, regional wall motion abnormality, poor graft flow

Emboli (air, clot, particulate matter)

ECG, TOE, graft flow

ECG changes, regional wall motion abnormality, poor graft flow

Technical graft anastomotic tissues

ECG, TOE, graft flow

ECG changes, regional wall motion abnormality, poor graft flow

Kink/clotting of bypass grafts, native vessels

ECG, TOE, graft flow, inspection

ECG changes, regional wall motion abnormality, poor graft flow

   Incomplete revascularization

Non-graftable vessels

Known intrinsic disease

   Metabolic

Hypoxia, hypercarbia

ABG, electrolytes, check ventilation

Hypokalemia, hyperkalemia

Electrolytes

   Uncorrected pathology

Hypertrophic cardiomyopathy

TOE

Abnormal outflow gradient, SAM

Valve gradients

TOE

Abnormal valve gradient

Shunts

TOE

Abnormal Doppler jet

   Mechanical issues

Prosthetic valve function

TOE

Poor leaflet motion, abnormal gradient

Intracardiac shunt (ASD, VSD)

TOE

Abnormal Doppler jet

   Conduction issues

Bradycardia

ECG

Heart rate less than 60

Atrioventricular dissociation

ECG

Third degree heart block

Atrial fibrillation

ECG, ABG, electrolytes

Hypoxia, electrolyte abnormality

Ventricular arrhythmias

ECG, ABG, electrolytes

Hypoxia, electrolyte abnormality

Vasodilation

Transpulmonary thermodilation, Swan-Ganz monitoring

Decreased systemic vascular resistance

Hypovolemia

Stroke volume monitoring

Decreased stroke volume, increased SVV

   Pulmonary hypertension

Pre-existing elevated pulmonary pressures, hypoxia, hypercarbia, fluid overload

ABG

Elevated pulmonary artery pressures, hypoxia, hypercarbia, RV distention

   Right ventricular failure

Elevated pulmonary pressures, inadequate myocardial protection, emboli to native or bypass circulation, fluid overload

Swan-Ganz monitoring, ABG, TOE

RV distention, poor RV wall motion, elevated pulmonary artery pressure, elevated central venous pressure