how does cardioplegia solution work

Cardioplegic - Clinical Pharmacology. Cardioplegic solution with added sodium bicarbonate when cooled and instilled into the coronary artery vasculature, causes prompt arrest of cardiac electromechanical activity, combats intracellular ion losses and buffers ischemic acidosis.

Full Answer

What is cardioplegia solution a used for?

Cardioplegia Solution ‘A’ is a sterile nonpyrogenic solution in a Viaflex bag. It is used to induce cardiac stasis and to protect the myocardium during open heart surgery. Cardioplegia Solution ‘A’ is an isotonic crystalloid solution based on extracellular fluid ionic concentrations.

How is cardioplegia used to induce cardiac arrest?

Cardioplegia is used on CPB to induce an arrest of the heart. Components of cardioplegia solution are varied in different institutions but include potassium to achieve diastolic arrest. A cross-clamp is applied to the ascending aorta, and the cardioplegia is administered into the aortic root in an antegrade fashion via the coronary ostia.

How is Cold cardioplegia administered?

Cold cardioplegia is given into the heart through the aortic root. Blood supply to the heart arises from the aortic root through coronary arteries. Cardioplegia in diastole ensures that the heart does not use up the valuable energy stores (adenosine triphosphate). Blood is commonly added to this solution in varying amounts from 0 to 100%.

What is cardioplegia mechanism?

Cardioplegia Mechanism. It is derived that presence of high concentration of potassium in solution prevents repolarization of cells. Also the muscle fibers do not respond any kind of stimuli. When membrane potential is at resting state, the sodium channels are blocked and as a result the cardiac arrest occurs.

What does cardioplegia solution do?

Solution. Cardioplegia Solution A is a sterile, non-pyrogenic solution for cardiac perfusion in a Viaflex bag. It is used to induce cardiac stasis and to protect the myocardium during open-heart surgery.

How is cardioplegia solution administered?

Anterograde cardioplegia is administered into a small cannula placed in the ascending aorta or directly into the coronary ostia. Retrograde cardioplegia is delivered through a catheter placed through the right atrium into the coronary sinus. Cardioplegia is then delivered into the venous system of the heart.

How do doctors induce cardioplegia for open-heart surgery?

Hyperkalemic, hypothermic solutions are frequently used to induce cardioplegic arrest and protect the heart during cardiac surgery involving CPB.

How does del Nido cardioplegia work?

Anaerobic glycolysis and its production of ATP has been shown to be inhibited by excess hydrogen ion accumulation (17,27,28). The del Nido cardioplegia mix incorporates sodium bicarbonate as a buffering solution to scavenge excess hydrogen ions and to assist in maintaining intracellular pH.

Why does cardioplegia stop the heart?

Cardioplegia lowers the metabolic rate of the heart muscle, thereby preventing cell death during the ischemic period of time.

What drug is used for cardioplegia?

Cardioplegic Solution is a sterile, nonpyrogenic, essentially isotonic, formulation of electrolytes in water for injection. It is a "core solution" intended for use only after addition of sodium bicarbonate to adjust pH prior to administration.

How many types of cardioplegia are there?

Cardioplegia administration can be anterograde, retrograde, or both. The anterograde cardioplegia is inserted in the proximal aorta and contains three lumens: one to administer the cardioplegia, another for suctioning, and the third to measure intraluminal pressure.

How is the heart restarted after bypass surgery?

It circulates blood through the body while moving blood away from the heart. The surgeon then operates on a heart that isn't beating and doesn't have blood flow. After surgery, the surgeon disconnects the device and the heart starts to work again.

How does potassium cause cardioplegia?

The persistence of potassium reduces the membrane potential and does not allow for adequate repolarization. This, in turn, creating a diastolic cardiac arrest.

What is del Nido used for?

We have found that del Nido cardioplegia allows us to customize myocardial protection for adult cardiac procedures. Like with any myocardial protection strategy, adequate and uniform distribution of cardioplegia solution to the myocardium is critical.

What is del Nido?

Del Nido cardioplegic solution (DNC), a blood-and-crystalloid solution, is used as a single-dose antegrade infusion to induce rapid cardiac arrest and provide at least 90 minutes of myocardial protection in neonatal heart surgery.

Who invented cardioplegia?

The term cardioplegia (cardio, heart and plegia, paralysis) was first introduced by Lam in 1957 (Lam et al., 1957), yet the method of arrest has its roots in the early experiments of British physiologist Sidney Ringer using the frog heart (Figure 2).

How do you prepare a cardioplegia solution?

It is required that 10 mL (840 mg) of 8.4% Sodium Bicarbonate Injection, USP (10 mEq each of sodium and bicarbonate) be added aseptically and thoroughly mixed with each 1000 mL of cardioplegic solution to adjust pH.

How do you prepare for cardioplegia?

make the solution, add the following to 1 liter of dH 2 O while mixing using a magnetic stirrer: 0.99 g of glucose (5.50 mM), 0.13 g of magnesium sulfate (0.50 mM), 1.79 g of potassium chloride (24.00 mM), 1.68 g of sodium bicarbonate (20.00 mM), 6.37 g of sodium chloride (109.00 mM), 0.12 g of sodium phosphate ...

What is a cardioplegia cannula?

Cardioplegia cannula is needed to deliver infusion during cardiac surgery. Additional equipment to have readily available includes an aortic cross-clamp, cannulas for arterial and venous access, and accessory cannulas for initiation and maintenance of cardiopulmonary bypass.

What are the types of cardioplegia?

type of cardioplegia – blood cardioplegia (BL) vs. crystalloid cardioplegia (CR = St. Thomas cardioplegia + Fresenius cardioplegia) = “Cardiopl_double”; or blood cardioplegia vs. St.

What are the chemical components of cardioplegia?

Chemical components added to the cardioplegia solution, such as potassium and glucose, are largely responsible for this protective effect. Basic characteristics of cardioplegia solutions include temperature, osmolarity, and pH.

What is the role of pharmacist in cardioplegia?

The pharmacist's role in the formulation, preparation, and quality control of cardioplegia solution is also discussed. The use of cardioplegia solution has substantially increased the safety of cardiac surgery.

How does a syringe protect the myocardium?

It protects the myocardium by inducing a rapid and complete diastolic arrest, minimizing myocardial energy requirements and preventing ischemic damage during the arrest phase, and minimizing or preventing reperfusion injury once coronary blood flow is restored.

How is cardioplegia delivered?

Cardioplegia is delivered under pressure to the heart via either a pressurized bag or a roller pump system. The advantages of roller pump system include easy incorporation of a continuous cooling system to maintain cardioplegia hypothermia, easy incorporation of the mixing apparatus necessary for blood cardioplegia systems, ...

What are the components of cardioplegia?

Components of cardioplegia solution are varied in different institutions but include potassium to achieve diastolic arrest. A cross-clamp is applied to the ascending aorta, and the cardioplegia is administered into the aortic root in an antegrade fashion via the coronary ostia.

What is retrograde delivery?

Cardioplegia Delivery Routes#N#Retrograde cardioplegia, where a cardioplegia catheter is introduced into the coronary sinus, allows for almost continuous cardioplegia administration. Retrograde delivery is useful in settings where antegrade cardioplegia is problematic, such as with severe aortic insufficiency or during aortic root or aortic valve surgery (Box 23-3 ). It also allows the distribution of cardioplegia to areas of myocardium supplied by significantly stenosed coronary vessels. Retrograde cardioplegia has proved safe and effective for cardioplegia in patients with coronary artery disease and in those undergoing valve surgery. With the administration of retrograde cardioplegia, certain provisos should be considered. The acceptable perfusion pressure to limit perivascular edema and hemorrhage needs to be limited to less than 40 mmHg. 17

What are the disadvantages of hypothermic cardioplegia?

The other disadvantages of hypothermic cardioplegia, in addition to the production of the metabolic inhibition in the myocardium, are an increase in plasma viscosity and a decrease in red blood cell deformability. As a result, investigations aimed at using warmer cardioplegia temperatures have been explored.

What is the temperature of myocardial solution?

The composition of cardioplegia solutions varies considerably; in contrast, myocardial temperature during cardioplegia is almost uniformly reduced to between 10°C and 12°C or less by the infusion of refrigerated cardioplegia and external topical cooling with ice slush.

Why do we need a pump for cardioplegia?

Cardioplegia must be delivered accurately to prevent myocardial damage, and new pump delivery systems provide a better operator-interface for effective delivery .

What temperature is used for cardioplegia?

Although hypothermic cardioplegia is the most commonly used temperature, numerous investigations have examined tepid (27–30°C) and warm (37–38°C) temperature ranges for the administration of cardioplegia.

What does cardioplegia mean?

Overview. The word cardioplegia combines the Greek cardio meaning the "heart", and plegia "paralysis". Technically, this means arresting or stopping the heart so that surgical procedures can be done in a still and bloodless field. Most commonly, however, the word cardioplegia refers to the solution used to bring about asystole of the heart, ...

What happens to potassium in cardioplegic solution?

Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of cardiac cells. The normal resting potential of ventricular myocytes is about -90 mV. When extracellular cardioplegia displaces blood surrounding myocytes, the membrane voltage becomes less negative and the cell depolarizes more readily. The depolarization causes contraction, intracellular calcium is sequestered by the sarcoplasmic reticulum via ATP-dependent Ca 2+ pumps, and the cell relaxes (diastole). However, the high potassium concentration of the cardioplegia extracellular prevents repolarization. The resting potential on ventricular myocardium is about −84 mV at an extracellular K + concentration of 5.4 mmol/l. Raising the K + concentration to 16.2 mmol/l raises the resting potential to −60 mV, a level at which muscle fibers are inexcitable to ordinary stimuli. When the resting potential approaches −50 mV, sodium channels are inactivated, resulting in a diastolic arrest of cardiac activity. Membrane inactivation gates, or h Na + gates, are voltage dependent. The less negative the membrane voltage, the more h gates that tend to close. If partial depolarization is produced by a gradual process such as elevating the level of extracellular K +, then the gates have ample time to close and thereby inactivate some of the Na + channels. When the cell is partially depolarized, many of the Na + channels are already inactivated, and only a fraction of these channels is available to conduct the inward Na + current during phase 0 depolarization.

How to do asystole?

The most common procedure for accomplishing asystole is infusing cold cardioplegic solution into the coronary circulation. This process protects the myocardium, or heart muscle, from damage during the period of ischemia. To achieve this, the patient is first placed on cardiopulmonary bypass.

What is a temporary cessation of cardiac activity?

Cardioplegia is intentional and temporary cessation of cardiac activity, primarily for cardiac surgery .

What is antegrade cardioplegia?

This is further augmented by the cardioplegia component which is high in potassium. When solution is introduced into the aortic root (with an aortic cross-clamp on the distal aorta to limit systemic circulation), this is called antegrade cardioplegia.

What does cold fluid do to the heart?

The cold fluid (usually at 4 °C) ensures that the heart cools down to a temperature of around 15–20 °C, thus slowing down the metabolism of the heart and thereby preventing damage to the heart muscle. This is further augmented by the cardioplegia component which is high in potassium.

What cations can be used to arrest the heart?

The use of two other cations, Na + and Ca 2+, also can be used to arrest the heart. By removing extracellular Na + from perfusate, the heart will not beat because the action potential is dependent upon extracellular Na + ions. However, the removal of Na + does not alter the resting membrane potential of the cell.

What is the primary goal of cardioplegia?

Cardioplegia is an essential component of cardiopulmonary bypass and with the primary goal to reduce myocardial oxygen demand by creating electrical quiescence and cooling the heart to reduce the ischemic effects of being on bypass.

What is the treatment for cardiac arrest?

Cardioplegia is a pharmacological therapy administered during cardiac surgery to intentionally and temporarily arrest the heart. The first solution used during cardiopulmonary bypass was reported by Dr. Melrose in the early 1950s, who identified that high levels of potassium citrate induced a reversible cardiac arrest.

Is potassium a common ion in cardioplegia?

As the solution diffuses and there is a washout of its components along with products of anaerobic cellular metabolism, electrical activity begins to appear, and redosing of cardioplegia is required if clinically indicated. Potassium, however, is not the only ion commonly found in cardioplegia.

Does potassium cause cardiac arrest?

These voltage-gated channels are targeted with cardioplegia to induce cardiac arrest. The persistence of potassium reduces the membrane potential and does not allow for adequate repolarization. This, in turn, creating a diastolic cardiac arrest.

What is the Baxter Cardioplegia Solution A?

Sodium chloride, potassium chloride, calcium chloride dihydrate and magnesium chloride hexahydrate. 2 Qualitative and Quantitative Composition. Baxter Cardioplegia Solution A is a sterile, non-pyrogenic solution in a Viaflex bag. It is used to induce cardiac stasis and to protect the myocardium during open-heart surgery.

How long does it take to mix Baxter Cardioplegia?

It should be cooled to 4°C before use. Once mixed, the solution should be used within 24 hours. It should not be used in serial connections with other containers.

What is the role of calcium in reperfusion?

Calcium. Calcium helps maintain the integrity of the cell membrane and prevents a condition known as "calcium paradox" occurring during reperfusion. Bicarbonate. This is added to adjust the pH, producing a slightly alkaline (7.4 - 7.8) solution and to compensate for the metabolic acidosis which accompanies ischaemia.

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Immunoglobulin (Ig) products provide critical therapy for people with immunodeficiencies and immune-type neurological conditions.

What is the purpose of sodium bicarbonate in cardioplegic solution?

Cardioplegic Solution with added sodium bicarbonate when cooled and instilled into the coronary artery vasculature, causes prompt arrest of cardiac electromechanical activity, combats intracellular ion losses and buffers ischemic acidosis. When used with hypothermia and ischemia, the action may be characterized as cold ischemic potassium-induced cardioplegia.

What is Baxter Cardioplegic Solution?

Baxter Cardioplegic Solution is a sterile, nonpyrogenic, essentially isotonic, formulation of electrolytes in Water for Injection, USP. It is a “core solution” intended for use only after addition of sodium bicarbonate to adjust pH prior to administration. After buffering with sodium bicarbonate it is suitable for cardiac instillation ...

Why is sodium important in myocardial fluid?

Sodium is essential to maintain ionic integrity of myocardial tissue. The chloride ions are present to maintain the electroneutrality of the solution. Added bicarbonate (HCO 3-) anion is included as a buffer to render the solution slightly alkaline and compensate for the metabolic acidosis that accompanies ischemia.

Why should myocardial temperature be monitored during surgery?

Myocardial temperature should be monitored during surgery to maintain hypothermia.

How to protect pharmaceutical products from heat?

Exposure of pharmaceutical products to heat should be minimized. Avoid excessive heat. Protect from freezing. It is recommended that the product be stored at room temperature (25°C); however, brief exposure up to 40°C does not adversely affect the product.

How much solution is instilled during bypass?

Development of severe hypotension and metabolic acidosis while on bypass has been reported when large volumes (8 to 10 liters) of solution are instilled and allowed to enter the pump and then the systemic circulation. Right heart venting is therefore recommended.

Can you instill sodium bicarbonate in the heart?

Do not instill the solution into the coronary vasculature unless sodium bicarbonate has been added. If large volumes of cardioplegic solution are infused and allowed to return to the heart lung machine without any venting from the right heart, then plasma magnesium and potassium levels may rise.

Why is cold solution used in cardioplegia?

Cardioplegia Mechanism. The cold solution is used to protect heart cells from dying. The presence of potassium in cold solution, reduces the membrane potential of myocardial cells and the depolarization of cells occur more rapidly. This depolarization causes the calcium to pump out and cells to contract more and as a result the cells feel relaxed.

What is the difference between cardioplegia and plegia?

Cardioplegia is a state of heart in which the activity of heart is ceased intentionally before surgical operation. It is also known as paralysis of heart . As the name indicates, cardio means “heart” and plegia means “paralysis”. The heart activity is ceased so that the surgery can be performed properly with no excessive blood loss.

How fast does antegrade cardioplegia take?

The pressure required for the injection of solution is 60 to 100 mm Hg. The arresting time in antegrade Cardioplegia is fast and may be ranging between 30 to 60 sec. if there is any delay in cardiac arrest then following reasons could be behind it; Problem in delivery system and AR is unrecognized.

What is retrograde cardioplegic?

When the cardioplegic solution is entered into the circulation via coronary sinus then this is known as retrograde Cardioplegia. The pressure required for injection of solution should be 30 to 50 mm Hg and higher pressure than this range can cause injury to the coronary sinus. The flow rate is 200 to 400 mL/min. if the pressure gets low than this range there could be following problems;

How to achieve cardiac paralysis?

Cardiac paralysis also known as cardiac asystole, can be achieved by introducing solution into the patient’s body specifically in the coronary artery circulation. This solution is responsible for making the heart survive in ischemic phase during surgery as this solution provide oxygen and all nutrients to heart cells not letting them die. The solution used for this purpose is cold solution. Change in ECG will show that the solution is working and heart paralysis.

Why is potassium in solution important?

It is derived that presence of high concentration of potassium in solution prevents repolarization of cells. Also the muscle fibers do not respond any kind of stimuli. When membrane potential is at resting state, the sodium channels are blocked and as a result the cardiac arrest occurs.

Does cardioplegia help with surgery?

Cardioplegia provide following benefits during surgery: It causes rapid, immediate electromechanical quiescence and also sustain it. It maintains the additives, added to balance the therapeutics, in concentration which is effective. It wash out the inhibitors of metabolism side by side.

Summary

Physiology

Cardioplegic solution is the means by which the ischemic myocardium is protected from cell death. This is achieved by reducing myocardial metabolism through a reduction in cardiac work load and by the use of hypothermia.
Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of cardiac cells. The normal resting potential of ventricular myoc…

Overview

Alternatives to cardioplegia

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