Cardiovascular Flashcards
Right ventricular failure physiology
Fails and dilates; blood backs up into right atrium and to the superior vena cava and inferior vena cava, causing jugular vein distention and hepatic congestion
Causes of Right ventricular failure
Right ventricular infarction, pulmonary embolus, elevated pulmonary pressure
Treatment for Right ventricular failure
Volume
Goals of Critical care
Enhance oxygen delivery; decrease oxygen demand
Diastole
Phase of the heart when the heart muscle relaxes and allows the chambers to fill with blood
Systole
Phase of the heart where the heart muscle contracts and pumps blood from the chambers into the arteries
Normal ejection fraction range
> 60%
Pulse Pressure
Difference between systolic and diastolic represents the force that the heart generates each time it contracts
Left Ventricular failure physiology
Fails and dilates; blood backs up into the left atrium and to the pulmonary veins, causing increased pulmonary pressures and pulmonary edema
Causes of Left Ventricular failure
Acute left ventricular infarction; cardiomyopathies
Treatment for Left Ventricular failure
Fluid restriction, diuresis
Right coronary artery
Perfuses the right atrium and right ventricle; 90% of people this is the dominant coronary artery and perfuses the inferior left ventricle
Left Coronary Artery
Left main artery
Left circumflex
Perfuses the left atrium and lateral wall of the left ventricle
Left anterior descending
Perfuses the anterior and apex of the left ventricle, as well as two-thirds of the ventricular septum
Coronary Artery Perfusion Pressure
Diastolic blood pressure - pulmonary artery wedge pressure
Normal Coronary Artery Perfusion Pressure
60-80 mmHg
Determinants of Ventricular Function
Supply of oxygen must equal demand of oxygen; heart utilizes approximately 85% of available oxygen at rest; when the myocardium requires more oxygen for proper functioning, the coronary arteries dilate in response to increased demand
Determinants of Ventricular Function
Supply of oxygen must equal demand of oxygen; heart utilizes approximately 85% of available oxygen at rest; when the myocardium requires more oxygen for proper functioning, the coronary arteries dilate in response to increased demand
Most likely cause of sudden heart rate rise
tissue hypoxia
Most likely cause of sudden respiratory rate rise
Tissue hypoxia and metabolic acidosis
Most likely cause of sudden temperature rise
Increase in oxygen requirements
Left ventricular end diastolic pressure
Important measure of ventricular performance and may identify patients at increased risk for developing late clinical symptoms of heart failure
Cardiac Output
Stroke volume X Heart rate
Indicate perfusion to the cells
Cardiac Output and Cardiac Index
Stroke Volume
Equals the amount of blood ejected with each ventricular contraction
Three things that determine stroke volume
Preload; afterload; contractility
Preload
The amount of volume returned to the ventricle at the end of diastole
Afterload
Impedance of ventricular emptying, resistance to ventricular ejection; workload of the ventricle to pump blood out