ICU Flashcards
Right ventricle determines?
Flow
Left ventricle determines?
Pressure
Adaptive changes in chronic heart failure?
- Fluid retention
- Increased oxygen extraction
- Renin-Angiotensin up-regulation
Etiology of heart failure?
- Ischaemic cardiomyopathy (dilation)
- Aortic stenosis (Hypertrophy & dilation)
- Hypertension (Hypertrophy & dilation)
- AF & arrhythmias
Treatment for chronic heart failure?
- ACE inhibitors
- Diuretics
- Calcium channel blockers
- Beta-blockers
Etiology of Acute heart failure?
- ACS
- Post-op cardiac surgery
- Sepsis
- COPD/ARDS
- Chest trauma
Hypotension is ?
SBP < 90 mmHg or decrease in baseline > 30mmHg
Forresters classification of heart failure?
- Class 1 = < 18 (PCWP) > 2.2 (CI) - Normal
- Class 2 = > 18 (PCWP) > 2.2 (CI) - Pulmonary congestion
- Class 3 = < 18 (PCWP) < 2.2 (CI) - Cardiac failure
- Class 4 = > 18 (PCWP) < 2.2 (CI) - Cardiogenic shock
Mortality in forresters classification?
- Class 1 < 3%
- Class 2 9%
- Class 3 23%
- Class 4 51%
Pulmonary artery occlusion pressure AKA?
Pulmonary Capillary Wedge Pressure
Determinants of LV function?
- Contractility
- Preload (End-diastolic volume)
- Afterload (Wall stress)
- Heart rate
- Synchrony
Starling’s law?
Describes preload
Anrep effect ?
Describes contractility
Factors increasing contractiity ?
- Autonomic tone / Increase - Exercise, stress / Decrease - Diabetes
- Catecholamines/ Decreased n chronic HF
- Catecholamine receptors / Decrased in sepsis
- Coronary blood flow / Increases contractility
- Serum calcium / Decreased contractility with hypocalcaemia
Compliance of the heart?
Determined by the change in volume to pressure
Causes of decrease in LV compliance ?
Primary
- Ischaemia
- LV hypertrophy
- Stunned myocardium
Secondary
- RV dilation (Pulmonary HTN, Volume overload)
- Hyperinflation
- Tamponade
Laplace’s law? Determinant of afterload
- Wall stress
- Tension = P x r
Afterload reduction ? Functions?
- Decreases wall stress
Chronotropy?
Increasing HR with increased contractility
HR and LVH?
Increasing HR decreases contractility