RxPG - Complications of Acute Myocardial Infarction

CHEST PAIN:

N.B. Ischaemic until proven otherwise.

ISCHAEMIC:

? angina - within ten days of M.I. _ if refractory / at rest / minimal activity > Angiography ? M.I. extension - approx 20 % of post thrombolysis pt's - ST / T wave changes in affected leads - ? re - thrombolysis / PTCA

NON - ISCHAEMIC:

Pericarditis: Early:- - friction b/w inflamed / dyskinetic epicardium and pericardium - usually assoc. with transmural M.I. Signs:- pain assoc. movement / inspiration / sharp / ST segment elevation - "concave" / non - localized plus/minus "friction rub". Temperature Late:- "Dresslers" Syndrome Occurs 1 - 4 wks post M.I. / auto - immune reponse / assoc. pleuritis / exudate. Rx NSAID's / aspirin / plus or minus narcotics

ARRHYTHMIAS:

Major cause of death post M.I. Increased myocardial stress - raised MVO2 - low diastolic filling

SINUS TACHYCARDIA:

- normal physiologic response with LV damage which lowers the threshold for VF - may be assoc. with pericarditis / stress / pain Beta blockers indicated if persistent - reduces mortality

PAC's/ STV's:

- uncommon - may be other risks assoc. - usually benign

A FIB / A FLUTTER:

- usually assoc. with CHF - increased risk of thrombus formation - anti - coag / digitalize

VENT ARRHYTHMIAS:

- 75 % incidence following M.I. - VE's / VT / V Fib - primary VF - 1 st 24/24 (10 % incidence) > irritability assoc. with cardiac cause - R on T 's

BRADYARRHYTHMIA:

- common post inf M.I. - vagus nerve involvement

A / V BLOCKS:

- inferior M.I. uncommon - anterior M.I. - poor prognosis - symptomatic Rx

BBB'S:

- assoc. poor prognosis - 6 mths

THROMBOEMBOLISM:

MURAL THROMBOSIS:

(sub endo clot in chamber) - assoc. with mod - large LV M.I. - increased risk of CVA - diff to detect Rx systemic anti - coagulation DVT: - Rx early ambulation

MYOCARDIAL DYSFUNCTION: depends on M.I. size, assoc. factors / ongoing assessment during acute phase of M.I. CCF: > 20 % of LV affected

CARDIOGENIC SHOCK:

> 40 % myo damage / poor prognosis / > 80 % mortality / swan ganz monitoring - medical Mx - nitrates / diuretics / inotropes - I.A.B.P. - augments coronary artery flow / decreased afterload augments forward flow

R) VENTRICULAR FAILURE:

r) ventricular M.I. increased JVP with no LV Failure Mx filling

MECHANICAL DEFECTS:

LV ANEURYSM:

assoc. with large LV M.I.

high risk of mural thrombus formation

high risk of rupture

Dx ECG - persisting ST elevation in chest leads

echocardiography

? CXR

Angiogram

PAPILLARY MUSCLE RUPTURE:

rare

usually posterio - medial LV muscle

partial / complete

usually assoc. with multi - vessel disease

Dx sudden deterioration in condition - APO

sudden loud systolic murmur

large 'v' waves on PCP trace

Rx medical emergency / swan ganz insertion / afterload reduction / surgical repair if indicated

VENT SEPTAL DEFECT:

uncommon

usually occurs within a week of M.I.

Left > Right shunt occurs

severity depends on size of rupture

Dx sudden deterioration/ loud pcp - systolic murmur of left sternal border/ mixed venous blood gas sampling/ RA / arterial / PA/

Rx afterload reduction - I.A.B.P/ caution with inotropes/ surgical repair

VENTRICULAR RUPTURE:

sudden / fatal/ common elderly/ preceded by increased pain/ brady / EMD/ massive tamponade results/

PERICARDIAL TAMPONADE:

assoc. with rupture or acute pericarditis/ hemodynamic deterioration +++++/ equilibrium of R & L pressures/ Kussmaul sign/ Pulsus paradoxus / faint heart sound/ Rx pericardiocentesis