Investigations of Cardiovascular Diseases 2023-2024 PDF

University of Baghdad College of Medicine 2023-2024 Title: Investigations of Cardiovascular Diseases Grade: Fourth Year Module: Systemic Module Speaker: Professor Muataz Fawzi Hussein Date: ...

University of Baghdad College of Medicine 2023-2024 Title: Investigations of Cardiovascular Diseases Grade: Fourth Year Module: Systemic Module Speaker: Professor Muataz Fawzi Hussein Date:  University of Baghdad/ College of Medicine 2022-2023 Learning Objectives 1. Outline the indications and contraindications of stress ECG 2. Outline the criteria of positive stress ECG 3. Outline the indications of ambulatory ECG monitoring 4. State the types of ambulatory ECG monitoring and advantage and disadvantage of each type. 5. Identify the role of BNP in diagnosis and management of heart failure 6. Enumerate the causes of elevated cardiac troponins 7. Outline the important chest X-ray findings in different cardiac diseases. 8. Outline the role of echocardiography in diagnosis of cardiac diseases. 9. State the indications of cardiac catheterization. 10. Identify the benefits of electrophysiological study in diagnosis and treatment of cardiac arrhythmias. 11. Outline the benefits of radionuclide imaging in diagnosis of cardiac diseases.  University of Baghdad/ College of Medicine 2022-2023 Specific investigations may be required to confirm a diagnosis of cardiac disease. Basic tests, such as electrocardiography, chest X-ray and echocardiography, can be performed in an outpatient clinic or at the bedside. Procedures such as cardiac catheterisation, radionuclide imaging, computed tomography (CT) and magnetic resonance imaging (MRI) require specialized facilities.  University of Baghdad/ College of Medicine 2022-2023 Exercise (stress) ECG Exercise electrocardiography is used to detect myocardial ischaemia during physical stress and is helpful in the diagnosis of coronary artery disease. A 12-lead ECG is recorded during exercise on a treadmill or bicycle ergometer. BP is recorded and symptoms assessed throughout the test. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Exercise (stress) ECG Common indications for exercise testing are: To confirm the diagnosis of angina To evaluate stable angina To assess prognosis following myocardial infarction To assess outcome after coronary revascularization, e.g. coronary angioplasty To diagnose and evaluate the treatment of exercise- induced arrhythmias  University of Baghdad/ College of Medicine 2022-2023 Exercise (stress) ECG A test is positive if: Anginal pain occurs and/or There are ST segment shifts of more than 1 mm High-risk findings: Low threshold for ischaemia (i.e. within stage 1 or 2 of the Bruce Protocol) Fall in BP on exercise Widespread, marked or prolonged ischaemic ECG changes Exercise-induced arrhythmia False negative and false positive results Unreliable population screening tool  University of Baghdad/ College of Medicine 2022-2023 Exercise (stress) ECG Stress testing is contraindicated in: Acute coronary syndrome Decompensated heart failure Severe hypertension Severe LV outflow obstruction Severe pulmonary hypertension  University of Baghdad/ College of Medicine 2022-2023 Ambulatory ECG Continuous (ambulatory) ECG recordings Obtained using a portable digital recorder. Can record for between 1 and 7 days. Indications: 1. investigation of patients with suspected arrhythmia 2. Assessment of rate control in patients with atrial fibrillation 3. Sometimes used to detect transient myocardial ischaemia using ST segment analysis University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Ambulatory ECG Patient-activated ECG recorders The patient places the device on the chest to record the rhythm during the episode. Used for patients with more infrequent symptoms Can be issued for several weeks until a symptom episode occurs. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Ambulatory ECG Implantable loop recorders Implanted subcutaneously Have a lifespan of 1–3 years Used to investigate patients with infrequent but potentially serious symptoms, such as syncope. University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Cardiac biomarkers Plasma or serum biomarkers can be measured to assess myocardial dysfunction and ischaemia. Brain natriuretic peptide University of Baghdad/ College of Medicine 2022-2023 This is a 32-amino acid peptide and is secreted by the LV along with an inactive 76-amino acid N-terminal fragment (NT-proBNP). NT-proBNP is diagnostically more useful, as it has a longer half-life. It is elevated principally in conditions associated with left ventricular systolic dysfunction, and may aid the diagnosis and assess prognosis and response to therapy in patients with heart failure. It differentiates between cardiac and respiratory causes of dyspnea in emergency setting  University of Baghdad/ College of Medicine 2022-2023 Cardiac troponins Troponin I and troponin T are structural cardiac muscle proteins that are released during myocyte damage and necrosis, and represent the cornerstone of the diagnosis of acute myocardial infarction (MI). Elevated plasma troponin concentrations are seen in other acute conditions, such as: Pulmonary embolus Septic shock and Acute pulmonary oedema.  University of Baghdad/ College of Medicine 2022-2023 Echocardiography Two-dimensional echocardiography Echocardiography is obtained by placing an ultrasound transducer on the chest wall to image the heart structures as a real-time, two-dimensional ‘slice’. This permits the rapid assessment of cardiac structure and function. Left ventricular wall thickness and ejection fraction can be estimated. University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Common indications for echocardiography Assessment of left ventricular function Diagnosis and quantification of severity of valve disease Identification of vegetations in endocarditis Identification of structural heart disease in atrial fibrillation, cardiomyopathies or congenital heart disease Detection of pericardial effusion Identification of structural heart disease or intracardiac thrombus in systemic embolism  University of Baghdad/ College of Medicine 2022-2023 Doppler echocardiography This depends on the Doppler principle that sound waves reflected from moving objects, such as intracardiac red blood cells, undergo a frequency shift. The speed and direction of the red cells, and thus of blood, can be detected in the heart chambers and great vessels. The greater the frequency shift, the faster the blood is moving. Doppler echocardiography can be used to detect valvular regurgitation, where the direction of blood flow is reversed and turbulence is seen, and is also used to detect high pressure gradients associated with stenosed valves. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Transesophageal echocardiography Transthoracic echocardiography sometimes produces poor images, especially if the patient is overweight or has obstructive airways disease. Some structures are difficult to visualize in transthoracic views, such as the left atrial appendage, pulmonary veins, thoracic aorta and interatrial septum. This produces high-resolution images, which makes the technique particularly valuable for investigating patients with: Prosthetic valve dysfunction Congenital abnormalities Aortic dissection Infective endocarditis and Systemic embolism (intracardiac thrombus or masses). University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Stress echocardiography Stress echocardiography is used to investigate patients with suspected coronary artery disease who are unsuitable for exercise stress testing, such as those with mobility problems or pre-existing bundle branch block. A two-dimensional echo is performed before and after infusion of a moderate to high dose of an inotrope, such as dobutamine. Myocardial segments with poor perfusion become ischaemic and contract poorly under stress, showing as a wall motion abnormality on the scan. Stress echocardiography is sometimes used to examine myocardial viability in patients with impaired left ventricular function. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Computed tomographic imaging Computed tomography (CT) is useful for imaging the cardiac chambers, great vessels, pericardium, and mediastinal structures and masses. Contrast scans are very useful for imaging the aorta in suspected aortic dissection, and the pulmonary arteries and branches in suspected pulmonary embolism. University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Some centres use cardiac CT scans for quantification of coronary artery calcification, which may serve as an index of cardiovascular risk. Modern multidetector scanning allows non-invasive coronary angiography with a spatial resolution approaching that of conventional coronary arteriography and at a lower radiation dose. CT coronary angiography is particularly useful in the initial elective assessment of patients with chest pain and a low or intermediate likelihood of disease, since its negative predictive value is very high: that is, excluding the presence of coronary artery disease. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Magnetic resonance imaging Magnetic resonance imaging (MRI) requires no ionizing radiation and can be used to generate cross-sectional images of the heart, lungs and mediastinal structures. MRI is very useful for: 1. Imaging the aorta, including suspected dissection. 2. Can define the anatomy of the heart and great vessels in patients with congenital heart disease. 3. It is also useful for detecting infiltrative conditions affecting the heart. 4. Allows quantification of blood flow across regurgitant or stenotic valves. 5. It is also possible to analyze regional wall motion in patients with suspected coronary disease or cardiomyopathy. 6. The RV is readily visualized with MRI. 7. MRI can also be employed to assess myocardial perfusion and viability. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Cardiac catheterization This involves passage of a preshaped catheter via a vein or artery into the heart under X-ray guidance, which allows the measurement of pressure and oxygen saturation in the cardiac chambers and great vessels, and the performance of angiograms by injecting contrast media into a chamber or blood vessel. Coronary angiography is the most widely performed procedure, in which the left and right coronary arteries are selectively cannulated and imaged, providing information about the extent and severity of coronary stenoses, thrombus and calcification. Left ventriculography can be performed during the procedure to determine the size and function of the LV and to demonstrate mitral regurgitation. Aortography defines the size of the aortic root and thoracic aorta, and can help quantify aortic regurgitation.  University of Baghdad/ College of Medicine 2022-2023 Right heart catheterization is used to assess right heart and pulmonary artery pressures, and to detect intracardiac shunts by measuring oxygen saturations in different chambers. Cardiac output can also be measured. Left atrial pressure can be measured directly by puncturing the interatrial septum from the RA with a special catheter. Swan–Ganz balloon catheters are often used to monitor pulmonary ‘wedge’ pressure as a guide to left heart filling pressure in critically ill patients. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Electrophysiology study Patients with known or suspected arrhythmia are investigated by percutaneous placement of electrode catheters into the heart via the femoral and neck veins. Electrophysiology study (EPS) is most commonly performed to evaluate patients for catheter ablation, normally done during the same procedure. It is occasionally used for risk stratification of patients suspected of being at risk of ventricular arrhythmias. University of Baghdad/ College of Medicine 2022-2023  University of Baghdad/ College of Medicine 2022-2023 Radionuclide imaging The availability of gamma-emitting radionuclides with a short half-life has made it possible to study cardiac function non-invasively. Two techniques are available, although their use is declining.  University of Baghdad/ College of Medicine 2022-2023 Blood pool imaging The isotope is injected intravenously and mixes with the circulating blood. A gamma camera detects the amount of radiation-emitting blood in the heart at different phases of the cardiac cycle, thereby permitting the calculation of ventricular ejection fractions. It also allows the assessment of the size and ‘shape’ of the cardiac chambers. Myocardial perfusion imaging This technique involves obtaining scintiscans of the myocardium at rest and during stress after the administration of an intravenous radioactive isotope, such as 99 technetium tetrofosmin.  University of Baghdad/ College of Medicine 2022-2023 More sophisticated quantitative information is obtained with positron emission tomography (PET), which can also be used to assess myocardial metabolism, but this is only available in a few centres. University of Baghdad/ College of Medicine 2022-2023 University of Baghdad/ College of Medicine 2022-2023