Cardiac Pharmacology Practice Test: Quiz!

The sinoatrial node, located in the right atrium of the heart, is responsible for initiating electrical impulses that regulate the heart's rhythm. These impulses cause the heart muscles to contract and pump blood. It acts as the pacemaker of the heart because it sets the pace for the rest of the heart's electrical system. The sinoatrial node generates regular impulses, which then travel through the atria and stimulate the atrioventricular node, Bundle of His, and Purkinje fibers, ultimately leading to coordinated contractions of the heart chambers.

Normal blood pressure is typically defined as 120/80, which represents the systolic pressure over the diastolic pressure. The systolic pressure is the force exerted on the walls of the arteries when the heart beats, while the diastolic pressure is the force when the heart is at rest between beats. A blood pressure reading of 120/80 is considered normal because it falls within the range of healthy blood pressure values.

Classical (stable angina) is the most common form of angina and it typically occurs during exertion, emotional stress, or indigestion due to excessive eating. It can be relieved by nitroglycerin and rest. This type of angina is characterized by predictable chest pain that occurs when the heart is working harder and needs more oxygen. It is usually caused by a blockage or narrowing of the coronary arteries, leading to reduced blood flow to the heart.

The volume of blood pumped out of the heart per minute is referred to as cardiac output. It is a measure of the efficiency of the heart in pumping blood throughout the body. Cardiac output is determined by multiplying the stroke volume (the amount of blood pumped out of the heart with each beat) by the heart rate (the number of heartbeats per minute). Therefore, cardiac output is the correct answer to the question.

Purkinje fibers are specialized cardiac muscle fibers that are responsible for transmitting electrical impulses throughout the heart. These fibers extend past the septum and branch out to innervate the rest of the heart, allowing for coordinated contraction and efficient pumping of blood. Unlike the sinoatrial node, bundle of His, and atrioventricular node, which are involved in initiating and regulating the heartbeat, the Purkinje fibers play a crucial role in conducting the electrical signals to ensure synchronized contraction of the heart muscle.

Beta adrenergic blockers are the correct answer because they decrease heart rate by blocking the action of epinephrine and norepinephrine on the beta receptors in the sympathetic nervous system. This action helps to reduce the workload on the heart and prevent the development of angina pectoris. Additionally, beta blockers can also reduce cardiac output by blocking the beta receptors in the heart, which leads to a decrease in contractility. This makes beta blockers an effective treatment option for myocardial infarction (MI). Calcium channel blockers, nitroglycerin, and morphine sulfate may also be used in the treatment of MI, but they do not specifically decrease heart rate by blocking the sympathetic nervous system like beta blockers do.

The amount of blood pumped by each ventricle per each contraction is known as stroke volume. It represents the volume of blood ejected from the ventricle with each heartbeat. Cardiac output refers to the total volume of blood pumped by the heart per minute, while blood volume refers to the total amount of blood in the body. Blood pressure, on the other hand, is the force exerted by circulating blood on the walls of blood vessels.

Verapamil (calan, isoptin) falls under the category of drugs that rely on the principle that calcium needs to move from the extracellular space into the intracellular space to create cardiac contractions. This drug blocks the calcium channels that are especially concentrated in the SA node and AV node, which results in the smoothing of cardiac muscles and dilation of blood vessels. Verapamil is commonly used to treat angina and lower blood pressure.

A myocardial infarction, commonly known as a heart attack, occurs when there is a prolonged restriction of oxygen to the heart, which ultimately leads to the death of heart tissue. This restriction can be caused by blockage of major arteries supplying blood to the heart.

Inotrophy refers to the force of muscle contraction. It is a term used to describe the ability of the heart or other muscles to contract with greater force. It is often used in the context of cardiac function, where inotropic agents can increase the force of contraction of the heart muscle. Inotropy is important for maintaining proper cardiac output and overall muscle function.

Nitroglycerin is the correct answer because it is a vasodilator that works by relaxing and widening blood vessels, which reduces the workload on the heart and improves blood flow. This medication is commonly used to treat stable angina and can alleviate chest pain by increasing the supply of oxygen to the heart muscle.

Unstable angina is the correct answer because it is characterized by chest pain that occurs at rest and is not relieved by rest or nitroglycerine. This type of angina is caused by significant coronary artery disease (CAD) and is often a warning sign that a myocardial infarction (MI) may be imminent.

The pressure created by the pumping action of the heart from one vessel to the next is known as blood pressure. Blood pressure is the force exerted by the blood against the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and consists of two values - systolic pressure (when the heart contracts) and diastolic pressure (when the heart relaxes). Blood pressure is an important indicator of cardiovascular health and can be influenced by factors such as heart rate, blood volume, and the elasticity of blood vessels.

Variant or vasospastic angina occurs due to arterial spasms caused by an obstruction in a coronary artery. This type of angina typically occurs at rest rather than during exertion. Unlike classical (stable) angina, which is triggered by physical activity or stress, variant angina is caused by the constriction of the coronary arteries, leading to reduced blood flow to the heart. This can result in chest pain or discomfort. Unstable angina, on the other hand, is characterized by chest pain that occurs at rest or with minimal exertion and is considered more severe and unpredictable than stable angina.

The atrioventricular (AV) node is responsible for delaying the transmission of impulses from fibers. This delay allows the atria to fully contract and empty all blood into the ventricles before ventricular contraction begins. By delaying the transmission, the AV node ensures that the atria and ventricles are in sync, allowing for efficient pumping of blood throughout the body.

The Bundle of His, also known as the atrioventricular bundle, is a group of specialized fibers located in the septum that divides the left and right ventricles of the heart. These fibers are found beneath the endocardium. The main function of the Bundle of His is to transmit electrical impulses from the atrioventricular node to the ventricles. These impulses allow for coordinated and synchronized contraction of the ventricles, ensuring efficient pumping of blood out of the heart.

Verapamil (calan, isoptin) is the correct answer because it is a calcium channel blocker that slows down the conduction of the AV node, leading to a decrease in heart rate and contractility. It also causes dilation of coronary arteries, improving blood flow to the heart. The mentioned side effects such as dizziness, sleepiness, headache, peripheral edema, hypotension, nausea, and constipation are commonly associated with the use of verapamil.

Atropine is a competitive antagonist for the muscarinic acetylcholine receptor. It is used to treat bradycardia, asystole, and pulseless electrical activity in cardiac arrest. Atropine blocks the action of the parasympathetic nervous system, which is responsible for slowing down the heart rate. By blocking the PNS, atropine speeds up the heart rate, helping to restore normal cardiac function in emergency situations.

Chronotrophy refers to the regulation of the heart rate. It involves the modulation of the rate of cardiac muscle contraction. Therefore, chronotrophy is the correct term to describe the rate of cardiac muscle contraction.

Amiodarone is the correct answer because it blocks both potassium ion channels and sodium ion channels. By blocking these channels, amiodarone prolongs the resting phase of heart contractions and the refractory period. This helps to regulate the heart's rhythm and is effective in treating dysrhythmias, particularly atrial dysrhythmias.

Dromotrophy refers to the conduction velocity of the AV node and the rate of electrical impulses in the heart. It is the correct answer because it specifically relates to the conduction velocity and electrical impulses in the AV node. Lustitrophy, chronotrophy, and inotrophy do not specifically pertain to the conduction velocity of the AV node and rate of electrical impulses in the heart.

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Amiodarone is the correct answer because it is a medication used to treat certain types of irregular heartbeats. Prolonged use of amiodarone can lead to a condition called Smurf Syndrome, where the skin turns blue-gray in color. This discoloration occurs due to the deposition of amiodarone and its metabolites in the skin, causing a change in pigmentation. Other drugs listed in the options do not cause this specific side effect.

Propranolol, also known as Inderal, is a non-selective beta-blocker that blocks both beta 1 and 2 receptors. It reduces the force of contraction and heart rate, making it effective in treating conditions such as tachycardia and hypertension. It is also used to prevent myocardial infarction (MI).

Epinephrine is a drug that is used to treat cardiac arrests and dysthymias by increasing peripheral resistance through alpha 1 adrenoreceptor vasoconstriction. This vasoconstriction causes blood to be shunted to the body's core, improving blood flow to vital organs and increasing blood pressure. Epinephrine is a sympathomimetic drug that mimics the effects of the sympathetic nervous system, leading to increased heart rate and contractility, bronchodilation, and vasoconstriction.

Quinidine is the correct answer because it is a drug that is approved for the treatment of atrial fibrillation. It works by blocking the fast inward sodium current, which helps to decrease the irregular contractions of the atria or ventricles. Additionally, Quinidine also decreases the contractile force of the heart rate and affects the myocardium and conduction system. Therefore, Quinidine is the appropriate drug for treating dysrhythmias such as atrial fibrillation.

The given answer lists four possible reasons for an acute MI (Myocardial Infarction). High consumption of fatty foods can lead to the build-up of plaque in the arteries, which can eventually block blood flow to the heart. A sedentary lifestyle can contribute to obesity and high blood pressure, both of which are risk factors for MI. Increased oxygen demand that the heart cannot provide can occur during physical exertion or stress, leading to an imbalance between oxygen supply and demand. Decreased flow of oxygen-rich blood can result from a blockage or narrowing of the coronary arteries, preventing adequate blood flow to the heart muscle.

ACLS stands for Advanced Cardiovascular Life Support, which is a protocol used in emergency situations where a combination of manual defibrillation and cardiac drugs like epinephrine and atropine are required. Cold blue, on the other hand, is not a term used in medical context and does not relate to the given question.

The drugs Quinidine, Lidocaine, Phenytoin, Propranolol, Procainamide, and Verapamil are used for Dysarthymias. These medications are commonly prescribed to treat dysarthria, a condition characterized by difficulty in controlling the muscles used for speech. Quinidine, Lidocaine, Phenytoin, Propranolol, Procainamide, and Verapamil help in managing the symptoms of dysarthria and improving speech clarity.

Propranolol is a beta-blocker medication commonly used to treat conditions such as high blood pressure, migraines, and anxiety. One of the main side effects of Propranolol is hypotension, which refers to low blood pressure. This can cause dizziness, lightheadedness, and fainting. Another side effect is bradycardia, which is a slower than normal heart rate. This can result in fatigue, weakness, and shortness of breath. Propranolol can also lead to diminished sex drive, causing a decrease in sexual desire or performance. Additionally, it can decrease renin secretion, which can affect kidney function.

The prehypertensive range refers to blood pressure readings that are slightly higher than normal but not yet considered to be in the hypertensive range. This range is typically defined as having a systolic blood pressure (top number) between 120 and 140 mmHg and a diastolic blood pressure (bottom number) between 80 and 90 mmHg. It serves as a warning sign that blood pressure levels are elevated and may indicate an increased risk for developing hypertension if not properly managed.

Hypertension, commonly known as high blood pressure, is diagnosed when the blood pressure readings consistently measure above 140/90 mmHg. This means that the systolic pressure (top number) is over 140 mmHg and the diastolic pressure (bottom number) is over 90 mmHg. These elevated readings indicate that the force of blood against the artery walls is higher than normal, which can lead to various health complications if left untreated. Therefore, any blood pressure measurement exceeding 140/90 mmHg is considered hypertension.

Verapamil is a medication used to treat high blood pressure, angina, and certain heart rhythm disorders. It belongs to a class of drugs called calcium channel blockers. The side effects listed in the answer are common side effects of Verapamil. Constipation is a possible side effect due to the medication's effect on smooth muscle in the intestines. Hypotension refers to low blood pressure, which can occur as Verapamil relaxes and widens the blood vessels. Peripheral edema is the swelling of the extremities, such as the legs and feet, caused by fluid retention. Nausea is another potential side effect of Verapamil.