Atrial fibrillation Coronary artery anatomy
Give 10–20mmol K+ via central line to get serum K+ 4.5–5.0mmol/L. Give empirical 20mmol Mg+ via Left main stem (LMS): arises from ostium of left sinus of Valsalva
central line if none given post-op. Give 300mg amiodarone IV over 1h in pt with good LV, followed by anteriorly and left atrial (LA) appendage to left AV groove, dividin
900mg amiodarone IV over 23h. circumflex (Cx), and occasionally a 3rd artery (intermediate). As it
In pt with poor LV function, give digoxin in 125mcg increments IV every 20min until rate control is supply to LV, occlusion can be fatal; severe left main disease =‘th
obtained, up to a maximum of 1500mcg in 24h. LAD runs down anterior interventricular groove to apex of heart
Synchronized DC cardioversion for unstable patients. to posterior interventricular groove. Variable number of diagona
of LV, small branches supply anterior surface of RV, and superior
perpendicularly to supply anterior 2/3 of interventricular septum
Profound hypotension Circumflex originates at 90* from LMS; runs medially to LA appe
Get immediate help. Quickly assess pulse, rhythm, rate, CVP, O2 sats, & bleeding. Defibrillate VF or posterior left AV groove to crux of heart. Occlusions of Cx àpost
pulseless VT, treat AF. Treat bradycardia with atropine 0.3mg IV or pace. Give gelofusine to raise CVP hearts (5–10%), the Cx turns 90* into posterior interventricular g
to 12–16mmHg, place bed head down. If suspect cardiac tamponade prepare for re-sternotomy. If pt artery (PDA). In 85–90% of hearts, PDA arises from right coronary
warm & vasodilated, draw up 10micrograms of metaraminol into 10mL of saline; give 1mL t/ central About 5% of hearts are co-dominant.
line, and flush. If pt still profoundly hypotensive, give 1mL 1:10 000 adrenaline IV. A variable number of obtuse marginals (OMs) arise from Cx to su
= AV nodal artery in which 45% course round LA near the AV gro
The RCA arises from ostium in right sinus of Valsalva, gives off inf
Bleeding to SAN, and runs immediately into deep right AV groove where i
• Get immediate help if bleeding is >400mL in 30min RV wall. Occlusions of RCA à inferior infarcts and bradycardia.
• Give gelofusine to get CVP 10–14 and systolic BP 80–100mmHg. Acute marginal = large branch which crosses acute margin of hea
• Order further 4U of blood, 2U FFP, and 2 pools platelets. reaches crux of hearts where it turns 90* to form PDA, which run
• Send clotting and FBC, request a CXR. groove.
• Rransfuse to achieve Hb >8.0g/dL, plt>100 x 109/L, APTT <40. Inferior septals, which supply inferior 1/3 of interventricular sep
• Give empirical protamine 25mg IV. AV node artery is given off by the RCA in 55% at the crux.
• Emergency re-exploration is indicated for excessive bleeding.
Poor urine output
Check that the Foley catheter is patent.
If the patient is hypotensive, treat this first.
Give a fluid challenge of gelofusine to raise the CVP to 14mmHg.
If not hypotensive and CVP >14mmHg, give 20mg furosemide IV.
Principles of cardiac surgery
Majority of procedures are coronary artery bypass graft (CABG) operations, followed by aortic valve Cardioplegia
replacements, and mitral valve (MV) repair and replacements. CPB does not stop heart; it just bypasses beating heart. If surgeo
Many pt are elderly with multiple comorbidities; 90% should be out of ICU within a day or two, and CPB gives surgeon three options: fibrillate the heart, cool the pat
ready to go home in a week. Cardioplegic arrest is by far the commonest technique.
Preoperative preparation Cardioplegia is a potassium rich solution. It can be based on bloo
Careful preop work-up is essential. All investigations must be checked; small abnormalities which better). It can be warm or cold (cold may reduce ischaemic injury
would not cause a problem in other specialties can have catastrophic results in cardiac surgery. coronary arteries, either anterogradely by inserting a cannula int
Full history: Quantify symptoms, previous MI or stroke. Comorbidities (esp COPD, renal failure, distal to the cardioplegia cannula or retrogradely via the coronar
peripheral vascular disease), MI <90 days (which incs mortality), drugs (aspirin, clopidogrel, and continuously or intermittently, every 20min or so. Cardioplegia a
warfarin normally stopped 5 days preop to reduce bleeding), allergies, recent chest infxn. Valve pt myocardial ischaemia.
must have been cleared by dentist. Ask about previous heart surgery, varicose vein surgery.
Full examination: signs of HF. Active infxn, e.g. abscess = relative CI to valve replacement. Look at
conduit: any evidence of varicose veins? Post-operative management
Investigations: All should have FBC, U&E, LFTs, clotting screen. Cross-match 2U of blood. ECG and Most patients are well enough to be extubated within 6h, leave
CXR. All pt undergoing coronary artery surgery and pt >35y undergoing valve surgery should have within 5 days. Stable patients should have bloods, CXRs, and ECG
coronary angiogram less than 1y-old. Pts undergoing valve surgery must have had an echo. First 6 hours
Carotid duplex in any pt with hx of stroke, TIA, or carotid bruits; some centres perform these • Myocardial function deteriorates due to ischaemia-reperfus
routinely in patients >70y old. • Inotropic support and pacing may be required.
Consent by registrar or consultant. • Patient should be fit for extubation by 6h post-op.
Sliding scale for diabetic patients • Patients should have diuresis >1mL/kg/h.
• Mediastinal bleeding should steadily decrease.
• Insulin requirements usually increase.
Cardiopulmonary bypass (CBP) Days 1–2
Any op that inv stopping/ opening heart (valve surgery, surgery on septal defects) or great vessels • Inotropes and pacing weaned, invasive monitoring lines rem
(ascending and arch aortic dissection and aneurysm surgery, resection of some tumours invading • Chest drains removed after 2h of zero drainage.
great vessels, e.g. renal cell) req CPB to maintain blood flow. This involves: • Catheter and any epidural removed, patient mobilized.
• Heparinizing pt so that blood does not clot in the CPB circuit. • PCA morphine reduced to oral analgesia.
• Securing a 24F aortic cannula in the ascending aorta. • Patient should be on aspirin, low molecular weight heparin,
• Securing a 32F venous cannula in the RA or SVC and IVC • Patient normally eating and drinking.
• Connecting both cannulae to the bypass circuit. Days 3–5
• The venous return from body is siphoned into bypass circuit. • Temporary pacing removed if ECG satisfactory.
• The venous blood is oxygenated, filtered, and can be cooled or warmed, and is pumped back • Valve repair patients should undergo echocardiography.
to the pt via aortic cannula. • Physiotherapists assess exercise tolerance.
• At end of bypass, heparin is reversed with protamine. • Back to baseline weight, medications stabilized, ready for di
Complications of CPB: stroke (atheromatous emboli, hypoperfusion, air, microemboli), SIRS, renal
and pulmonary dysfunction
Pathophysiology of CPB: CPB is unavoidable for many operations. It has a major impact on nearly
Give 10–20mmol K+ via central line to get serum K+ 4.5–5.0mmol/L. Give empirical 20mmol Mg+ via Left main stem (LMS): arises from ostium of left sinus of Valsalva
central line if none given post-op. Give 300mg amiodarone IV over 1h in pt with good LV, followed by anteriorly and left atrial (LA) appendage to left AV groove, dividin
900mg amiodarone IV over 23h. circumflex (Cx), and occasionally a 3rd artery (intermediate). As it
In pt with poor LV function, give digoxin in 125mcg increments IV every 20min until rate control is supply to LV, occlusion can be fatal; severe left main disease =‘th
obtained, up to a maximum of 1500mcg in 24h. LAD runs down anterior interventricular groove to apex of heart
Synchronized DC cardioversion for unstable patients. to posterior interventricular groove. Variable number of diagona
of LV, small branches supply anterior surface of RV, and superior
perpendicularly to supply anterior 2/3 of interventricular septum
Profound hypotension Circumflex originates at 90* from LMS; runs medially to LA appe
Get immediate help. Quickly assess pulse, rhythm, rate, CVP, O2 sats, & bleeding. Defibrillate VF or posterior left AV groove to crux of heart. Occlusions of Cx àpost
pulseless VT, treat AF. Treat bradycardia with atropine 0.3mg IV or pace. Give gelofusine to raise CVP hearts (5–10%), the Cx turns 90* into posterior interventricular g
to 12–16mmHg, place bed head down. If suspect cardiac tamponade prepare for re-sternotomy. If pt artery (PDA). In 85–90% of hearts, PDA arises from right coronary
warm & vasodilated, draw up 10micrograms of metaraminol into 10mL of saline; give 1mL t/ central About 5% of hearts are co-dominant.
line, and flush. If pt still profoundly hypotensive, give 1mL 1:10 000 adrenaline IV. A variable number of obtuse marginals (OMs) arise from Cx to su
= AV nodal artery in which 45% course round LA near the AV gro
The RCA arises from ostium in right sinus of Valsalva, gives off inf
Bleeding to SAN, and runs immediately into deep right AV groove where i
• Get immediate help if bleeding is >400mL in 30min RV wall. Occlusions of RCA à inferior infarcts and bradycardia.
• Give gelofusine to get CVP 10–14 and systolic BP 80–100mmHg. Acute marginal = large branch which crosses acute margin of hea
• Order further 4U of blood, 2U FFP, and 2 pools platelets. reaches crux of hearts where it turns 90* to form PDA, which run
• Send clotting and FBC, request a CXR. groove.
• Rransfuse to achieve Hb >8.0g/dL, plt>100 x 109/L, APTT <40. Inferior septals, which supply inferior 1/3 of interventricular sep
• Give empirical protamine 25mg IV. AV node artery is given off by the RCA in 55% at the crux.
• Emergency re-exploration is indicated for excessive bleeding.
Poor urine output
Check that the Foley catheter is patent.
If the patient is hypotensive, treat this first.
Give a fluid challenge of gelofusine to raise the CVP to 14mmHg.
If not hypotensive and CVP >14mmHg, give 20mg furosemide IV.
Principles of cardiac surgery
Majority of procedures are coronary artery bypass graft (CABG) operations, followed by aortic valve Cardioplegia
replacements, and mitral valve (MV) repair and replacements. CPB does not stop heart; it just bypasses beating heart. If surgeo
Many pt are elderly with multiple comorbidities; 90% should be out of ICU within a day or two, and CPB gives surgeon three options: fibrillate the heart, cool the pat
ready to go home in a week. Cardioplegic arrest is by far the commonest technique.
Preoperative preparation Cardioplegia is a potassium rich solution. It can be based on bloo
Careful preop work-up is essential. All investigations must be checked; small abnormalities which better). It can be warm or cold (cold may reduce ischaemic injury
would not cause a problem in other specialties can have catastrophic results in cardiac surgery. coronary arteries, either anterogradely by inserting a cannula int
Full history: Quantify symptoms, previous MI or stroke. Comorbidities (esp COPD, renal failure, distal to the cardioplegia cannula or retrogradely via the coronar
peripheral vascular disease), MI <90 days (which incs mortality), drugs (aspirin, clopidogrel, and continuously or intermittently, every 20min or so. Cardioplegia a
warfarin normally stopped 5 days preop to reduce bleeding), allergies, recent chest infxn. Valve pt myocardial ischaemia.
must have been cleared by dentist. Ask about previous heart surgery, varicose vein surgery.
Full examination: signs of HF. Active infxn, e.g. abscess = relative CI to valve replacement. Look at
conduit: any evidence of varicose veins? Post-operative management
Investigations: All should have FBC, U&E, LFTs, clotting screen. Cross-match 2U of blood. ECG and Most patients are well enough to be extubated within 6h, leave
CXR. All pt undergoing coronary artery surgery and pt >35y undergoing valve surgery should have within 5 days. Stable patients should have bloods, CXRs, and ECG
coronary angiogram less than 1y-old. Pts undergoing valve surgery must have had an echo. First 6 hours
Carotid duplex in any pt with hx of stroke, TIA, or carotid bruits; some centres perform these • Myocardial function deteriorates due to ischaemia-reperfus
routinely in patients >70y old. • Inotropic support and pacing may be required.
Consent by registrar or consultant. • Patient should be fit for extubation by 6h post-op.
Sliding scale for diabetic patients • Patients should have diuresis >1mL/kg/h.
• Mediastinal bleeding should steadily decrease.
• Insulin requirements usually increase.
Cardiopulmonary bypass (CBP) Days 1–2
Any op that inv stopping/ opening heart (valve surgery, surgery on septal defects) or great vessels • Inotropes and pacing weaned, invasive monitoring lines rem
(ascending and arch aortic dissection and aneurysm surgery, resection of some tumours invading • Chest drains removed after 2h of zero drainage.
great vessels, e.g. renal cell) req CPB to maintain blood flow. This involves: • Catheter and any epidural removed, patient mobilized.
• Heparinizing pt so that blood does not clot in the CPB circuit. • PCA morphine reduced to oral analgesia.
• Securing a 24F aortic cannula in the ascending aorta. • Patient should be on aspirin, low molecular weight heparin,
• Securing a 32F venous cannula in the RA or SVC and IVC • Patient normally eating and drinking.
• Connecting both cannulae to the bypass circuit. Days 3–5
• The venous return from body is siphoned into bypass circuit. • Temporary pacing removed if ECG satisfactory.
• The venous blood is oxygenated, filtered, and can be cooled or warmed, and is pumped back • Valve repair patients should undergo echocardiography.
to the pt via aortic cannula. • Physiotherapists assess exercise tolerance.
• At end of bypass, heparin is reversed with protamine. • Back to baseline weight, medications stabilized, ready for di
Complications of CPB: stroke (atheromatous emboli, hypoperfusion, air, microemboli), SIRS, renal
and pulmonary dysfunction
Pathophysiology of CPB: CPB is unavoidable for many operations. It has a major impact on nearly
