Cardiac Mechanics and Function

Which factor is NOT an important mechanism for changing the force of cardiac contraction?

Which factor primarily regulates the contractility of the heart?

Which factor determines the overlap of actin and myosin in cardiac muscle?

What is the molecular makeup of the muscle that can influence the mechanical properties of the heart?

Which factor can change the mechanical properties of the twitch contraction in the heart?

Which factor is an important determinant of ventricular force generation?

What determines the size of the Ca transient in the heart?

Which type of muscle is easily stretched at short muscle lengths?

What is the protective mechanism in the whole heart that prevents overfilling?

What are isometric contractions in cardiac muscle?

What determines the force generating capabilities of striated muscle?

What is the relationship between resting length and cardiac function called?

What is the sarcomere length beyond which it is very difficult to stretch resting cardiac muscle?

What is the primary factor that regulates force development in cardiac muscle?

What is the characteristic of resting cardiac muscle compared to skeletal muscle at sarcomere lengths near the peak of the length-active force relationship?

What are the factors that regulate force development in cardiac muscle?

Which phase of the cardiac cycle is represented by the bottom side of the pressure-volume loop?

What does the width of the pressure-volume loop represent?

Which event occurs at the time represented by the corner of the pressure-volume loop labeled 'AC'?

What determines the rate and magnitude of shortening in cardiac muscle?

What happens to the velocity and magnitude of shortening as the afterload increases?

Which type of muscle only functions on the 'ascending limb' of the length-tension relationship?

What is the name of the loop that can be used to plot the instantaneous pressures and volumes throughout the cardiac cycle?

When does the muscle shorten at a maximal rate?

Which one of these is true about the relationship between afterload and the velocity of shortening in cardiac muscle?

What is the diastolic pressure-volume relationship (DPVR) in cardiac muscle?

A decrease in diastolic ventricular compliance is represented by what?

What can cause a decrease in diastolic ventricular compliance in cardiac muscle?

What does the end-systolic pressure-volume relationship (ESPVR) represent in cardiac muscle?

How is the end-systolic pressure-volume relationship (ESPVR) derived in cardiac muscle?

What happens to the maximum capability of the ventricle to develop pressure as the volume of the ventricle decreases in cardiac muscle?

What happens to the velocity and magnitude of shortening as the afterload increases in cardiac muscle?

Which of the following is true about compliance in cardiac muscle?

What is the relationship between ventricular ejection and the end-systolic pressure-volume relationship (ESPVR)?

What is contractility in cardiac muscle?

Which of the following is true about the regulation of contractility in cardiac muscle?

What are some indices used to estimate changes in contractility?

What happens to stroke volume when contractility increases with no change in preload or afterload?

How can contractility be modified in cardiac muscle?

What happens to contractility in cardiac diseases?

What causes reduced myofilament Ca binding affinity in cardiac muscle?

What is associated with reduced levels of SERCa2 and 'depressed' Ca handling in cardiac muscle?

Which of the following is true about failing hearts?

What is preload in the context of the heart?

How is preload best represented?

What happens when there is an increase in preload (EDV)?

What physiological factors can alter preload?

What is the problem with using end-diastolic pressure (EDP) as a measure of preload when diastolic compliance is changing?

What can happen when + inotropic drugs are used to correct abnormal contractility in human heart failure?

What is the effect of an increase in end-diastolic volume (EDV) on the PV loop?

What is the term for the reduced contractility in failing hearts?

Why is correcting abnormal contractility in human heart failure not easily accomplished?

Which of the following is a measure of afterload in the heart?

What is the formula for mean blood pressure (MBP)?

In patients with hypertension, increased afterload is primarily due to what factor?

What happens to stroke volume when afterload is increased, while preload and contractility are held constant?

What is the formula for cardiac output (CO)?

What controls heart rate in normal people?

What effect does increased sympathetic nerve activity have on heart rate?

What is the formula for calculating systolic ventricular wall stress?

What happens to the velocity of muscle fiber shortening when afterload is increased?

Which of the following is true about congestive heart failure (CHF)?

What is the result of decreased parasympathetic nerve activity near the SA node?

What happens to stroke volume, cardiac output, and blood pressure when the time available for ventricular filling is reduced?

What is the primary cause of congestive heart failure (CHF)?

What is the effect of increased end-diastolic volume (EDV) on the pressure-volume loop?

What is the characteristic of the failing cardiac myocytes in congestive heart failure (CHF)?

What is the relationship between heart rate and time for ventricular filling?

What happens to the pressure generating capability of the ventricle as it dilates?

What is the result of increased end-diastolic pressure (EDP)?

What is the effect of increased exercise intensity on cardiac output?

Which of the following is a cause of increased afterload in patients with hypertension?

What happens to stroke volume when afterload is increased?

Why does decreased stroke volume occur when afterload is increased?

Which of the following can be used to assess afterload in the heart?

Which of the following represents the pressure which the ventricle must overcome to begin ejection in the heart?