Principles Of Cardiology III- Test I

Tachycardia refers to an abnormally fast heart rate. When the heart beats faster, the filling time of the ventricles decreases. This means that there is less time for the ventricles to fill with blood during diastole. As a result, the amount of blood pumped out of the heart with each beat (stroke volume) decreases. Since perfusion refers to the delivery of blood to tissues, a decrease in stroke volume leads to a decrease in coronary artery perfusion. Therefore, tachycardia will have a negative effect on coronary artery perfusion.

The pressure loop represents Mitral Stenosis because it shows a decrease in pressure during diastole, which is characteristic of this valvular disorder. Mitral Stenosis occurs when the mitral valve becomes narrowed, making it difficult for blood to flow from the left atrium to the left ventricle. This results in increased pressure in the left atrium and decreased pressure in the left ventricle during diastole.

Hypokinesis refers to a decreased contraction of the ventricles. This means that the ventricles are not contracting as strongly as they should be. This can be caused by a variety of factors, such as damage to the heart muscle or a decrease in blood supply to the heart. Hypokinesis can lead to decreased pumping of blood from the heart, which can result in symptoms such as fatigue, shortness of breath, and decreased exercise tolerance.

A decrease in heart rate will not cause an increase in myocardial oxygen consumption because when the heart rate decreases, the heart has more time to fill with blood during diastole. This allows for increased coronary perfusion and oxygen delivery to the myocardium, resulting in a decrease in oxygen demand.

The correct answer is to check lead placement and verify ST segment changes. This is because ST-segment elevation on the ECG can indicate myocardial ischemia or infarction, which is a serious condition that requires immediate attention. Checking the lead placement ensures that the ECG readings are accurate, while verifying the ST segment changes helps to confirm if there is indeed myocardial ischemia or infarction occurring. This information is crucial for determining the appropriate course of action and providing the necessary interventions to address the patient's condition.

The correct answer is Aortic Stenosis. Aortic stenosis is a valvular disorder characterized by the narrowing of the aortic valve, which leads to restricted blood flow from the left ventricle to the aorta. This results in increased pressure in the left ventricle during systole, as shown in the pressure loop. The pressure curve rises steeply during systole and then drops quickly during diastole, indicating the difficulty in pushing blood through the narrowed valve.

Oxygen demand is not a determinant of myocardial function because it refers to the amount of oxygen needed by the heart muscle to function properly, rather than directly affecting the heart's ability to contract and pump blood. The other options, such as preload, heart rate, and contractility, all directly influence myocardial function by affecting the force of contraction and the amount of blood pumped by the heart.

Mrs. B is the correct answer because she has major cardiac clinical predictors, specifically a history of atrial fibrillation and severe mitral stenosis. These conditions indicate significant cardiac dysfunction and increase the risk of cardiovascular events. The other patients do not have major cardiac clinical predictors mentioned in their medical history.

During the A-B segment of the cardiac pressure volume loop, the ventricles are in diastole and are filling with blood. This phase is known as the filling phase. The atria contract and push blood into the ventricles, causing the ventricular volume to increase while the ventricular pressure remains low. This allows for the passive filling of the ventricles before the next phase of the cardiac cycle.

During the C-D segment of the cardiac pressure volume loop, the ejection phase occurs. This is the phase where the ventricles contract and push blood out of the heart into the arteries. The pressure in the ventricles increases, causing the semilunar valves to open and blood to be ejected. The volume of blood in the ventricles decreases during this phase, leading to the ejection of blood.

METS are a physiological concept used to express the energy cost of physical activities as multiples of Resting Metabolic Rate. It is a unit of measurement that helps in determining the intensity of different physical activities and their impact on the body's energy expenditure. By calculating METS, healthcare professionals can assess the energy requirements and recommend appropriate physical activity levels for individuals. This concept is widely used in exercise physiology and clinical settings to guide exercise prescription and rehabilitation programs.

Based on the given ECG, the most likely occlusion is in the Right Coronary Artery. This is because the ECG shows ST-segment elevation in leads II, III, and aVF, which are typically affected by a right coronary artery occlusion.

Encephalopathy is a condition characterized by brain dysfunction, which can occur as a result of severe hypertension. Stage 4 hypertension is the most severe stage, where blood pressure is extremely high and can cause damage to various organs including the brain. Therefore, it is at this stage that a patient is most likely to experience encephalopathy.

Many patients with hypertension display an accentuated hypotensive response to induction, meaning their blood pressure drops significantly during the process. However, they also exhibit an exaggerated hypertensive response to intubation, where their blood pressure increases significantly. This suggests that these patients have a tendency to experience low blood pressure during induction and high blood pressure during intubation.

During the D-A segment of the cardiac pressure volume loop, isovolumetric relaxation occurs. This phase represents the period when the ventricles are in diastole and the pressure within the ventricles decreases while the volume remains constant. The mitral valve is closed, preventing blood from flowing into the ventricles, and the aortic valve is also closed, preventing blood from flowing out of the ventricles. This phase allows the ventricles to relax and refill with blood before the next contraction.

A bundle-branch block refers to a delay or blockage in the electrical signals that travel through the bundle branches of the cardiac conduction system. The bundle branches are responsible for conducting the electrical impulses from the atria to the ventricles. Purkinje fibers are a specialized network of cells that extend from the bundle branches and are responsible for transmitting the electrical signals to the ventricular muscle, causing it to contract. Therefore, a bundle-branch block most likely represents an issue with the Purkinje fibers.

The correct answer is -80 mv. Resting potential refers to the electrical charge difference between the inside and outside of a cell when it is at rest. In the case of the heart, a resting potential of -80 mv indicates that the inside of the heart cell is more negatively charged compared to the outside. This negative charge is essential for maintaining the normal electrical activity of the heart and allows it to contract and pump blood effectively.

During anesthetic management of a patient with hypertension, it is important to keep the intraoperative blood pressure within 20% of the baseline blood pressure. This means that the blood pressure should not deviate more than 20% from the patient's normal or baseline blood pressure. This is crucial to ensure that the patient's blood pressure remains stable and within a safe range during the procedure.

Dyskinesis refers to the paradoxical bulging of the ventricles. This condition occurs when a portion of the ventricular wall moves in the opposite direction of the rest of the ventricle during contraction. It is typically caused by a regional abnormality in the myocardium, such as scar tissue or aneurysm. Dyskinesis can impair the pumping function of the heart and lead to decreased cardiac output.

During systole, the heart muscle contracts and pumps blood out of the chambers and into the arteries. This contraction causes a temporary decrease in blood flow to the coronary arteries, which supply oxygen and nutrients to the heart muscle itself. This is because the contraction of the heart muscle compresses the coronary arteries, reducing the amount of blood that can flow through them. Therefore, the correct answer is systole.

Occlusion of the circumflex artery will result in a lateral wall MI. The circumflex artery is one of the main branches of the left coronary artery and supplies blood to the lateral wall of the left ventricle. When this artery becomes blocked, it causes a lack of blood flow to the lateral wall, leading to myocardial infarction in that area. Symptoms of a lateral wall MI may include chest pain, shortness of breath, and changes in the ECG readings.

The pressure loop shown in the question represents Mitral Regurge. This is indicated by the backward flow of blood from the left ventricle to the left atrium during systole. Mitral regurgitation occurs when the mitral valve does not close properly, allowing blood to leak back into the left atrium. This results in a characteristic pressure loop pattern, which is depicted in the given diagram.

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Hypertension, or high blood pressure, is the correct answer because it is a well-known risk factor for the development of coronary artery disease (CAD). Hypertension can cause damage to the walls of the arteries, leading to the formation of plaque and narrowing of the blood vessels. This can restrict blood flow to the heart, increasing the risk of CAD. Additionally, hypertension can also lead to other cardiovascular conditions such as heart failure and stroke, further contributing to the development of CAD. Family history, aortic stenosis, and a history of deep vein thrombosis (DVT) may also be risk factors for CAD, but hypertension is considered the primary risk factor.

Mrs. Ertha's condition indicates that she is severely impaired and requires total assistance for all activities of daily living. She is aphasic, uncommunicative, and unable to care for herself. She has contractures, a PEG tube, and wears diapers for incontinence. Additionally, she has had pneumonia and a healed ulcer in the past 3 years. These factors suggest a very low level of functioning, warranting a MET score of 1, indicating complete dependence on others for all activities.

The given answer "All the Above" is the correct answer because the statement "COMIC RELIEF: The perfect gift for any occasion..." suggests that the gift being referred to is something that can bring humor and laughter. The responses "Yeah!! I want it too!!", "Ha ha ha! I love SNL", and "OK, first you put 'Jizz in my pants' and now THIS?" all indicate a positive reaction to the idea of receiving the gift, reinforcing the idea that it is indeed suitable for any occasion. Therefore, the correct answer encompasses all of the given responses.

During the plateau phase of the cardiac action potential, L-type calcium channels open. This allows calcium ions to enter the cardiac cells, leading to a sustained depolarization of the cell membrane. This phase is characterized by a prolonged period of membrane potential, which helps in the contraction of the cardiac muscle and ensures efficient pumping of blood.

The correct answer is Mr. C, a 52 yr old male with a history of diabetes and peripheral neuropathy. Intermediate cardiac clinical predictors refer to conditions or factors that are associated with an increased risk of cardiac events or complications. In this case, diabetes and peripheral neuropathy are both conditions that can contribute to cardiovascular problems. While Ms. A and Mrs. B have their own medical histories, they do not have conditions that directly relate to cardiac risk. Therefore, Mr. C is the only patient among the options provided who has intermediate cardiac clinical predictors.

Stage 3 hypertension is characterized by a systolic blood pressure of 180 mmHg or higher, or a diastolic blood pressure of 110 mmHg or higher. At this stage, the blood pressure is severely elevated, which can lead to damage to the blood vessels in the kidneys. This damage can result in renal dysfunction, such as decreased kidney function or the development of chronic kidney disease. Therefore, it is at stage 3 of hypertension that a patient would begin to experience renal dysfunction.

Sympathetic stimulation of the SA node triggers the release of norepinephrine from nerve endings. Norepinephrine then binds to Beta 1 adrenergic receptors on pacemaker cell membranes. This binding activates a signaling cascade that leads to an increase in heart rate and contractility. Acetylcholine, on the other hand, is released during parasympathetic stimulation and has the opposite effect, slowing down the heart rate. Ephedrine is a sympathomimetic drug that stimulates the release of norepinephrine, but it is not directly released from nerve endings. cAMP is a secondary messenger involved in the signaling pathway activated by norepinephrine binding to the Beta 1 adrenergic receptors.

The mean arterial pressure (MAP) is calculated by adding twice the diastolic blood pressure (DBP) to the systolic blood pressure (SBP) and dividing the sum by 3. In this case, the DBP is 80 and the SBP is 134. Adding twice the DBP (80 x 2 = 160) to the SBP (134) gives a sum of 294. Dividing 294 by 3 gives a MAP of 98.

The AV node causes a delay in transmission of the action potential in the cardiac conduction system. This delay allows the atria to contract and empty their blood into the ventricles before the ventricles contract. This coordination ensures efficient blood flow and prevents the atria and ventricles from contracting at the same time, which could lead to ineffective pumping of blood.

During depolarization of cardiac cells, the sodium channels open, allowing sodium ions to enter the cell. This influx of sodium ions leads to an increase in the intracellular concentration of sodium. At the same time, the potassium channels also open, allowing potassium ions to exit the cell. This efflux of potassium ions leads to a decrease in the intracellular concentration of potassium. Therefore, the correct answer is Sodium, Potassium.

Based on the given ECG, the most likely occlusion is in the Left Anterior Descending (LAD) coronary artery. The ECG shows ST-segment elevation in leads V1-V6, which is characteristic of an anterior wall myocardial infarction. The LAD supplies blood to the anterior wall of the left ventricle, which explains the changes seen in the ECG.

Ephedrine is a sympathomimetic drug that acts on alpha and beta adrenergic receptors, causing vasoconstriction and increased heart rate. In this scenario, the patient is experiencing bradycardia (low heart rate) and hypotension (low blood pressure). Ephedrine can help increase the heart rate and improve blood pressure by stimulating the sympathetic nervous system. Therefore, giving Ephedrine 5-10 mg would be an appropriate treatment for this bradycardia.

Starling's Law states that the greater the amount of blood entering the heart during diastole, the greater the amount of blood ejected during systole. This means that the heart will pump out a larger volume of blood if it receives a larger volume of blood during the relaxation phase. This law helps to explain the relationship between the amount of blood entering the heart and the amount of blood pumped out, highlighting the importance of preload in cardiac function.

The Law of La Place states that there is a relationship between ventricular pressure and wall tension. This means that as ventricular pressure increases, the tension in the walls of the ventricles also increases. This relationship is important in understanding how the heart functions and how it is able to pump blood effectively.

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Stage 1 hypertension is defined as having a systolic blood pressure (the top number) between 130-139 mmHg or a diastolic blood pressure (the bottom number) between 80-89 mmHg. Among the given options, the blood pressure reading of 142/90 falls within this range, making it the correct answer for stage 1 hypertension.

The most important thing to do next is to give esmolol to treat the tachycardia. This is because the patient's heart rate is elevated at 136 beats per minute, which can be detrimental in the setting of an intra-op MI. Esmolol is a beta-blocker that can help decrease the heart rate and reduce the workload on the heart, improving myocardial oxygen supply and demand balance. This intervention should be prioritized to stabilize the patient's condition and prevent further complications.

In acute pulmonary edema, there is an increase in fluid accumulation in the lungs, leading to increased pressure in the pulmonary artery. This increased pressure is reflected in the readings of the Pulmonary Artery Catheter. CVP (Central Venous Pressure), PCWP (Pulmonary Capillary Wedge Pressure), and PAP (Pulmonary Artery Pressure) would all be expected to increase due to the elevated fluid volume and pressure in the pulmonary artery. On the other hand, CI (Cardiac Index) would decrease as the heart's ability to pump effectively is compromised by the increased fluid and pressure in the lungs.

Halothane is the correct answer because it causes the greatest amount of myocardial depression compared to the other anesthetics listed. Myocardial depression refers to a decrease in the contractility of the heart muscle, leading to a decrease in the pumping ability of the heart. Halothane is known to have a more pronounced negative inotropic effect on the heart, meaning it reduces the force of contraction. This can be problematic in patients with compromised cardiac function or those undergoing cardiac surgery, as it can further impair heart function. Sevoflurane, Desflurane, and Isoflurane also have some myocardial depressant effects, but to a lesser extent than Halothane.

Ischemia refers to a lack of blood flow to the tissues, which can lead to tissue damage. In the context of the question, ischemia would not cause an increase in pulmonary artery pressure because it does not directly affect the pulmonary circulation. Pulmonary artery pressure is primarily influenced by conditions such as left ventricular failure, mitral regurgitation, and pulmonary hypertension, which can all lead to increased pressure in the pulmonary arteries.

The appropriate range for PCWP (Pulmonary Capillary Wedge Pressure) readings is 5-15. This range is considered normal and indicates that the pressure in the left atrium and pulmonary capillaries is within a healthy range. Higher or lower readings may indicate abnormalities or health issues.

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A VDT pacemaker senses both the atria and the ventricles. This means that it can detect the electrical activity in both chambers of the heart. By sensing the activity in these chambers, the pacemaker can determine if the heart is beating too slowly or irregularly. It can then send electrical signals to stimulate the heart and regulate its rhythm. By sensing both chambers, the pacemaker can effectively monitor and control the overall function of the heart.

Fem-pop bypass is considered a high cardiac risk procedure because it involves bypassing a blocked or narrowed artery in the leg using a graft. This procedure requires the heart to pump blood through the graft, which puts additional strain on the heart. It is typically performed on patients with severe peripheral artery disease and significant cardiovascular risk factors. Carotid endarterectomy, mediastinoscopy, and left breast mastectomy are not specifically related to cardiac risk.

The given pressure loop represents Aortic Regurge. This can be determined based on the characteristics of the pressure loop, which typically shows a rapid drop in pressure during diastole due to the regurgitation of blood from the aorta back into the left ventricle. This causes an increase in left ventricular end-diastolic volume and pressure, leading to a rapid rise in pressure during systole. This pattern is consistent with Aortic Regurge.

During repolarization, the potassium ions inside the cell increase while the slow calcium channels close. This process allows the cell to return to its resting state by restoring the original electrical charge across the cell membrane. The increase in potassium ions helps to bring the membrane potential back to its negative value, while the closure of slow calcium channels prevents further calcium influx, which is responsible for depolarization.

The cardiac index is a measure of cardiac output adjusted for body surface area. It is calculated by dividing the cardiac output by the body surface area. In this case, the cardiac output can be calculated by multiplying the stroke volume (SV) by the heart rate (HR). The given values are BP 116/64, HR 58, SV 100, BSA 2 m2, and CVP 6. Using these values, the cardiac output can be calculated as 100 * 58 = 5800 ml/min. Dividing this by the body surface area of 2 m2 gives a cardiac index of 5800/2 = 2900 ml/min/m2, which is equivalent to 2.9 L/min/m2.