chest roentgenography, etc.
This chapter briefly describes the various clinical examination methods traditionally used by cardiologists in detecting heart diseases. It also explains various symptoms and physiological factors related to heart diseases and their clinical significance. In addition, the chapter also discusses the works in the literature that have integrated artificial intelligence and machine learning methods along with the clinically observed physiological values for improved detection of heart disease conditions.
2.2 Physical Assessments
As in past years, experts and doctors rely on many physical techniques as a path to early diagnosis of heart diseases. Physical assessments for diagnosing heart diseases include the technique, palpation, auscultation, electrocardiography, treadmill test, and cardiac biomarker examination. Each type of examination is chosen based on the result observed in the previous type. Usually, the inspection technique is conducted first and, based on its results, the licensed physician or cardiologist further proceeds with other types of examination.
2.2.1 Inspection Examination
This technique focuses on the visual appearance of the human patients, where the skin color, general health, face expressions, and nutritional status of the patient are taken into consideration. For instance, sweatiness, paleness, or cyanosis can be the initial signs of a possible heart attack in an acutely ill patient. Cyanosis is a medical condition where a bluish discoloration is seen in the lips, ears, nose, fingernails, as well as toenails. This condition is usually known as “blue hands or feet” due to hypoxemia. Hypoxemia is a condition where oxygen levels are lower than normal in the blood. The bluish color is caused by the excess amount of deoxyhemoglobin in the blood when various heart-related conditions prevent blood flow from tissues to the heart and backward. Excess amounts of deoxyhemoglobin in the blood can be due to various heart-related diseases including heart failure, myocardial infections, congenital heart diseases, valvular heart conditions, etc. Moreover, malar flush, corneal arcus, xanthomata, and proptosis are manifestations in the face of the patient suffering from heart disease. Malar flush is a facial manifestation where the cheeks turn a plum-red color. The malar flush symptom is closely related to valvular heart disease called mitral stenosis. Mitral stenosis is a condition where the mitral valve’s area is less than 2 cm2 (the normal area is about 5 cm2) during diastole. Reduction in the area causes carbon dioxide retention and leads to vasodilation (widening of blood vessels) of the arterioles present in the cheek. In the xanthomata condition, the eyes, palms, or tendons will experience a yellowish deposit of lipids. The excess yellowish deposit is due to high-level blood lipids and fats. The tendon xanthomata is a sign of high-level LDL (low-density lipoprotein) cholesterol in the blood as well as atherosclerosis. Proptosis refers to a change in the eyeball movement, especially to a protruded eyeball. In non-acute patients, one important sign is cachexia, as it is a clear sign for the prognosis of heart failure [1]. Cachexia is a wasting disorder where the patient experiences severe weight loss as well muscle loss.
2.2.2 Palpation Examination
Palpation examination involves pulse tracing of patients’ jugular veins, arterial pulses, precordial impulses, etc. This includes examination using the fingers or hands to test patients. Jugular veins can be tested by evaluating the internal jugular veins located in the patient’s neck. Whereas arterial pulse examination involves assessing the arteries located either in the hands or legs, assessment of the hand arteries can be measured by examining how fast or slow the heart rate is. This is done by placing fingers on the arteries located in the patient’s wrist and comparing the timing along with the consistency of the impulses. The physician can use their other hand to palpate the subjec patient’s other wrist to confirm the measurements. The heart rate is determined by counting the radial pulse for 30 seconds and then multiplying it by 2. This can give an accurate result except in the case of irregular rhythm.
2.2.3 Auscultation Examination
Auscultation means listening carefully to the heart sounds or murmurs through a stethoscope. The stethoscope tool consists of two parts: the bell and the diaphragm. Each part has its particular features, with the bell focusing on low-pitched sounds and detecting murmurs of aortic valve stenosis or carotid bruits, and the diaphragm focusing on high-pitched sounds that can detect valve closures or systolic clicks. During auscultation examination, the physician makes the patient lie in four different positions (shown in Figure 2.1): supine, upright, left lateral decubitus, and upright leaning forward [2]. The physician should be looking for irregular murmurs or heart sounds and identifying their location, duration, intensity, and pitch. This will all help in diagnosing heart conditions. Although irregular murmurs or heart sounds are not always linked with underlying heart conditions, they can, however, in certain conditions be an early warning of heart diseases.
Figure 2.1 Supine, left lateral decubitus, upright, and upright leaning forward positions.
2.2.4 Electrocardiogram (ECG)
This ECG is generated by a method called electrocardiography, where several electrodes are placed on the patient’s heart, legs, and arms and monitor the pulses for around 10 minutes. The technique measures the electrical activity of each heartbeat resulting in an electrocardiogram that shows the heart’s functionality. The electrocardiogram generated during the electrocardiography technique is a graph that depicts the characteristic of voltage versus time of the heart’s electrical activity. During each cardiac cycle, these electrodes detect the minor electrical changes that occur as a result of cardiac muscle depolarization and repolarization. Several cardiac anomalies, such as cardiac rhythm disruptions (e.g. atrial fibrillation and ventricular tachycardia), insufficient coronary artery blood flow (e.g. myocardial ischemia and myocardial infarction), and electrolyte disturbances (e.g. hypokalemia and hyperkalemia) cause changes in the usual ECG pattern. An illustration of the ECG test is shown in Figure 2.2. An ECG test is required only if the patient has any risk factors, such as hypertension, or physical discomforts, such as angina or palpitations including irregular heartbeats or rapid heartbeats. Patients with an existing history of heart disease are required to do the ECG test. Moreover, healthy individuals with a family history of heart disease are advised to do the ECG test if they are going to begin any heavy exercise routine or heavy labor routine.
Figure 2.2 ECG. E denotes electrodes placed for detecting the small electrical changes induced by cardiac muscle depolarization. The graph of voltage versus time of the heart’s electrical activity is showing in the ECG monitor. A physician/nurse is assigned to supervise the ECG test.
The major waves of a single ECG pattern and the normal values of ECG signals for normal heart rate are given in Figure 2.3. Arrhythmia is detected by verifying against the intervals shown in the table.
Figure 2.3 Major waves of a single ECG signal and the normal values of ECG signals.
2.2.5 Treadmill Test
The treadmill test is done by making patients walk briskly on a treadmill, which makes their hearts pump fast. The treadmill test is conducted to identify how well the heart of a patient handles their work and exercise capacity. During
