"The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next."
This topic covers the sequence of events that occur during one heart beat, including the phases of ventricular systole and diastole.
Anatomy of the Heart: This topic covers the structure of the heart, including its chambers, valves, and blood vessels.
Physiology of the Heart: This topic covers the functions and processes of the heart, including muscle contraction, blood flow, and oxygenation.
Hemodynamics: This topic covers the principles of blood flow and pressure within the cardiovascular system.
Cardiac Output and Stroke Volume: These topics cover how much blood is pumped out of the heart each minute and with each beat, respectively.
Blood Pressure: This topic covers the measurement and regulation of blood pressure within the cardiovascular system.
Heart Sounds: This topic covers the different sounds produced by the heart during the cardiac cycle and their significance.
ECG (Electrocardiogram): This topic covers the measurement and analysis of the electrical activity of the heart, including different waveforms and their importance.
Cardiac Arrhythmias: This topic covers abnormal rhythms of the heart and their potential causes, symptoms, and treatments.
Cardiopulmonary Resuscitation (CPR): This topic covers the basic life-saving skills used in emergency situations, including chest compressions and rescue breathing.
Cardiac Imaging: This topic covers various diagnostic imaging techniques used to visualize the heart and blood vessels, such as ultrasound, CT scans, and MRI.
Cardiac Medications: This topic covers the medications used to treat various cardiac conditions, including hypertension, angina, heart failure, and arrhythmias.
Cardiovascular Diseases: This topic covers various conditions that affect the cardiovascular system, such as atherosclerosis, coronary artery disease, and heart failure.
Exercise Physiology: This topic covers the effects of physical activity on the cardiovascular system, including changes in heart rate, blood pressure, and oxygen consumption.
Nutrition and Cardiovascular Health: This topic covers the role of diet and lifestyle factors in maintaining cardiovascular health and preventing heart disease.
Cardiac Rehabilitation: This topic covers the structured exercise and counseling programs used to help people recover from heart attacks, heart surgery, or other cardiac events.
Systole: This is the contraction phase of the heart. During systole, the ventricles contract, pushing blood out into the pulmonary artery and aorta. The atria are also contracting during this time, but this is a negligible contribution to the overall blood ejection.
Diastole: This is the relaxation phase of the heart. During diastole, the ventricles are relaxed and fill with blood from the atria. The atria have completed their contraction during the systole phase, and now they are also filling back up with blood from the venae cavae and pulmonary veins.
"It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, called systole."
"The heart muscle relaxes and refills with blood."
"The heart contracts and pumps blood."
"Each cardiac cycle, or heartbeat, takes about 0.8 second to complete the cycle."
"There are two atrial and two ventricle chambers of the heart."
"They work in concert to repeat the cardiac cycle continuously."
"The heart relaxes and expands while receiving blood into both ventricles through both atria."
"The two atria begin to contract (atrial systole), and each atrium pumps blood into the ventricle below it."
"The ventricles are contracting and vigorously pulsing (or ejecting) two separated blood supplies from the heart — one to the lungs and one to all other body organs and systems."
"The mitral and tricuspid valves open during ventricular diastole to permit filling."
"When prompted by electrical signals from the sinoatrial node, the ventricles start contracting (ventricular systole), and as back-pressure against them increases, the AV valves are forced to close, which stops the blood volumes in the ventricles from flowing in or out."
"Due to the contractions of the systole, pressures in the ventricles rise quickly, exceeding the pressures in the trunks of the aorta and the pulmonary arteries, and causing the requisite valves (the aortic and pulmonary valves) to open."
"This is the ejection stage of the cardiac cycle; it is depicted as the ventricular systole–first phase followed by the ventricular systole–second phase. After ventricular pressures fall below their peak(s) and below those in the trunks of the aorta and pulmonary arteries, the aortic and pulmonary valves close again."
"It is the stage during which pressure within the ventricles begins to fall significantly."
"The atria begin refilling as blood returns to flow into the right atrium (from the vena cavae) and into the left atrium (from the pulmonary veins)."
"The movements of cardiac muscle are coordinated by a series of electrical impulses produced by specialized pacemaker cells found within the sinoatrial node and the atrioventricular node."
"Cardiac muscle is composed of myocytes which initiate their internal contractions without applying to external nerves."
"Electrical systole initiates the atrial systole at the P wave deflection of a steady signal."
"It starts contractions (systole)."