hemodynamics and electrophysiology of heart.pptx

nukalapavan 1,379 views 17 slides Jul 19, 2024
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About This Presentation

This presentation gives a clear explanation of hemodynamics and cardiac electrophysiology which will be helpful for students of bpharmacy sem 5 as a part of the pharmacology. the presentation is explained diagramatically which makes ease for the students.


Slide Content

HEMODYNAMICS & ELECTROPHYSIOLOGY OF HEART BY: N J V S PAVAN M.PHARMACY HINDU COLLEGE OF PHARMACY GUNTUR, A.P, INDIA., 522002

HEMODYNAMICS Hemodynamics is how your  blood flows  through your arteries and veins and the forces that affect your blood flow. Normally, your blood flows in a laminar (streamlined) pattern. It flows fastest in the middle of a blood vessel, where there’s no friction with blood vessel walls. However, the flow is turbulent in your ventricles (lower  heart chambers ) and in places where a vessel branches off or changes in diameter. You’ll need to use more energy to move blood that has a turbulent flow because it’s not moving efficiently.

FLOW OF BLOOD IN HUMAN BODY

FLOW OF BLOOD IN HEART

BLOOD AND ITS COMPONENTS Blood is an essential life force, constantly flowing and keeping your body working. Blood is mostly fluid but contains cells and proteins that literally make it thicker than water. Blood has four parts: Red blood cells, white blood cells, platelets and plasma. Each part has specific and important tasks, from carrying oxygen to carrying out waste products. Your blood also acts like a kind of health barometer. Unusual blood test results may be the first sign of changes that could point to serious illness.

Functions of BLOOD Blood flowing through your  blood vessels  is responsible for many things: It carries oxygen and nutrients throughout your body. It forms  blood clots  to manage bleeding. It protects your body from infections. It carries waste products. It regulates your body temperature. Cardiac Output Cardiac output is how many liters of blood your heart pumps in one minute. Your healthcare provider can figure this out with this cardiac output equation: multiply stroke volume by heart rate.

HEMODYNAMIC FACTORS Hemodynamic factors are things that affect how well your blood flows. They can make it easier or harder for your blood to get to your organs and tissues. Your body makes constant adjustments to give your cells what they need. Hemodynamic factors include: The size (diameter) of a blood vessel. It’s easier for your blood to move through a larger or more open vessel. It’s harder for blood to flow through an artery that’s become narrow because of a plaque deposit containing cholesterol. The amount of friction your blood must overcome to keep moving. The friction of blood flowing against a blood vessel wall slows it down. Blood closer to your artery wall moves more slowly because of this friction. Blood in the middle of your artery moves faster. Blood vessel expansion and contraction in response to blood pressure changes. Your blood vessels have the ability to become wider or narrower to control blood flow and keep it consistent.

Pressure differences between how forcefully your heart pumps and how much resistance your blood vessels provide. The blood your heart pumps has to push against your blood vessels’ force. This is why having high blood pressure makes your heart work harder. Cardiac output. Your heart can pump out more or less blood with each heartbeat depending on what you’re doing at the time. When you exercise, your heart sends more blood to your cells because they need more oxygen than when they’re resting. Heart rate. Your heart can beat more times per minute when you’re exercising than when you’re resting. This helps your body get the increased amount of oxygen it needs for exercise. How well your heart’s ventricles are working. If you have a heart condition that makes your ventricles unable to pump blood well, this affects how much blood they can send to your body.

HEMODYNAMIC INSTABILITY Hemodynamic instability means your body can’t get enough blood flow. This is known as shock. There are several types, depending on the cause. Types of shock Cardiogenic. Hypovolemic. Obstructive. Distributive. Neurogenic.

ELECTROPHYSIOLOGY OF HEART

Cardiac electrophysiology is a branch of cardiology that studies, diagnoses, and treats heart conditions that affect the heart's electrical activity. This includes heart rhythm abnormalities, or cardiac arrhythmias, such as skipped beats, atrial fibrillation, and SVTs.

Your heart’s conduction system is the network of nodes (groups of cells that can be either nerve or muscle tissue), specialized cells and electrical signals that keep your heart beating. Two types of cells control your heartbeat: Conducting cells  carry the electric signals. Muscle cells  control your heart’s contractions. Your heart (cardiac) conduction system sends the signal to start a  heartbeat . It also sends signals that tell different parts of your heart to relax and contract (squeeze). This process of contracting and relaxing controls blood flow through your heart and to the rest of your body.

Your heart is a pump that sends blood through your body. For each heartbeat, electrical signals travel through the conduction pathway of your heart. It starts when your sinoatrial (SA) node creates an excitation signal. This electrical signal is like electricity traveling through wires to an appliance in your home. The excitation signal travels to: Your atria (top heart chambers), telling them to contract. The atrioventricular (AV) node, delaying the signal until your atria are empty of blood. The bundle of His (center bundle of nerve fibers), carrying the signal to the Purkinje fibers. The Purkinje fibers to your ventricles (bottom heart chambers), causing them to contract. These steps make up one full contraction of your heart muscle. Your heart conduction system sends out thousands of signals per day to keep your heart beating. ELECTRICAL CONDUCTION IN HEART

Repolarization is the process by which electrical charges in a cell return to their resting state. It's a stage of an action potential that occurs after depolarization, when the cell reaches its highest voltage. During repolarization, the cell's voltage decreases due to potassium (K+) ions moving out of the cell along its electrochemical gradient. This restores the difference in charge between the inside and outside of the cell membrane. Depolarization is caused by a rapid rise in membrane potential, which opens sodium channels in the cellular membrane and allows a large influx of sodium ions. This process can occur in excitable cells, such as neurons and muscle cells, which respond to electrical signals. Hyperpolarization is a phase in electrophysiology when the membrane potential of a neuron becomes more negative at a specific point. This happens when potassium ions leave the cell and potassium channels close, which can be caused by an increase in potassium permeability. Hyperpolarization can also occur during the final part of an action potential or in response to inhibitory neural messages.

RELATIONSHIP BETWEEN ECG AND CARDIAC CYCLE