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Restrictive cardiomyopathy

1 What is the basic pathophysiology in restrictive cardiomyopathy? The basic pathophysiology in restrictive cardiomyopathy is increased stiffness of the ventricular walls as a result of myocardial disease, leading to impaired diastolic filling of the ventricles. The result is a steep rise in diastolic pressure with small increases in volume (preload). Ejection fraction is usually preserved in most cases at least in the early stages but…

Hypertrophic cardiomyopathy

1 What is hypertrophic cardiomyopathy? Hypertrophic cardiomyopathy (HCM) is a primary cardiac disorder characterized by myocardial hypertrophy and a nondilated left ventricle (LV) in the absence of both an accountable increase in cardiac afterload (i.e., aortic stenosis or systemic hypertension) and an underlying systemic or metabolic disease. The hypertrophy is caused by a pathogenic variant of cardiac sarcomere proteins. Historically, and due to the fact that…

Heart failure with preserved ejection fraction

1 Describe diastolic dysfunction. Diastolic dysfunction (DD) is defined as increased viscoelastic chamber stiffness, impaired ventricular relaxation, or a combination of both. Decline in left ventricular (LV) compliance occurs with aging and may be accelerated by conditions such as hypertension, diabetes, and obesity. DD can occur in the absence or presence of systolic dysfunction and may not necessarily lead to clinical symptoms. However in some instances,…

LV dysfunction and dilated cardiomyopathy: Etiologies and evaluation

1 What is the definition and incidence of heart failure? Heart failure (HF) is a clinical syndrome resulting from progressive myocardial dysfunction that compromises ventricular filling and cardiac output. HF patients may be broadly categorized as having HF with preserved ejection fraction (HFpEF) defined as left ventricular ejection fraction (LVEF) >50% to 55%, or patients who have HF with reduced ventricular ejection fraction (HFrEF) defined as…

Myocarditis

1 What is myocarditis? Myocarditis is an inflammatory disease of the myocardium, which can occur as a result of exposure to a discrete external trigger or to antigens such as viruses, bacteria, parasites, toxins, or drugs, or as a result of an internal trigger, including autoimmune activation against self-antigens. The cardiac manifestations include acute heart failure, arrhythmias, atrioventricular (AV) block, sudden death, and chronic dilated cardiomyopathy.…

Coronary artery bypass surgery

1 What are the indications for coronary artery bypass grafting (CABG)? According to the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, class I indications for CABG include significant left main stenosis, three-vessel coronary artery disease (CAD), and two-vessel disease involving the proximal left anterior descending (LAD) artery. CABG should be considered as a reasonable treatment strategy (class IIa) in patients with single-vessel proximal LAD disease…

Percutaneous coronary intervention

1 What does the term percutaneous coronary intervention mean? Andreas Gruentzig performed the first successful balloon angioplasty procedure in humans in 1977. Initial coronary interventions involving only balloon angioplasty were referred to as percutaneous transluminal coronary angioplasty (PTCA). Since then, there have been considerable advances in the field of interventional cardiology. The development of coronary stents was a significant boost to interventional cardiology, addressing many of…

Cardiogenic shock

1 Define cardiogenic shock. Cardiogenic shock is a state of end-organ hypoperfusion due to cardiac failure and the inability of the cardiovascular system to provide adequate blood flow to the extremities and vital organs. In general, patients with cardiogenic shock manifest persistent hypotension (systolic blood pressure less than 80–90 mm Hg or a mean arterial pressure 30 mm Hg below baseline) with severe reduction in cardiac…

ST-elevation myocardial infarction

1 What are the electrocardiographic criteria for the diagnosis of ST-segment elevation myocardial infarction? Criteria for the diagnosis of ST-segment elevation myocardial infarction (STEMI) derive from criteria established for the administration of thrombolytic therapy, which evolved in the late 1980s and 1990s. Electrocardiographic (ECG) criteria for suspected coronary artery occlusion include: American College of Cardiology Foundation/American Heart Association (ACCF/AHA) criteria for STEMI consist of ST-segment elevation…

Non–ST-elevation acute coronary syndrome

1 What is non–ST-elevation acute coronary syndrome? It is now recognized that unstable angina, non–Q-wave myocardial infarction (MI), non–ST-segment elevation MI, and ST-segment elevation myocardial infarction (STEMI) are all part of a continuum of the pathophysiologic process in which a coronary plaque ruptures, thrombus formation occurs, and partial or complete, transient, or more sustained vessel occlusion may occur ( Fig. 16.1 ). This process is deemed…

Chronic stable angina

1 Can a patient with new-onset chest pain have chronic stable angina? The term “chronic stable angina” refers to angina that has been stable in frequency and severity for at least 2 months and with which the episodes are provoked by exertion or stress of similar intensity. Chronic stable angina is the initial manifestation of coronary artery disease (CAD) in about half of patients; the other…

Chest pains and angina

1 Are most emergency room visits for chest pain caused by acute coronary syndromes? No. Acute coronary syndromes (e.g., unstable angina, myocardial infarction) account for only a small percentage of emergency room (ER) visits for chest pain. Depending on the study, only a small percentage of patients (1%–11%) are diagnosed as having chest pains caused by coronary artery disease (CAD) or acute coronary syndrome (ACS). ACS…

Cardiac catheterization: Coronary angiogram, intracoronary imaging, and physiology

1 What constitutes cardiac catheterization? Cardiac catheterization typically includes the following four procedures: coronary angiogram, left heart catheterization, left ventricular (LV) angiogram, and right heart catheterization. Coronary angiogram refers to opacification of coronary arteries with iodinated contrast after selective cannulation using specialized end-hole catheters inserted via peripheral arterial access (usually femoral or radial). These catheters come in a wide variety of preformed shapes to help cannulate…

Bedside hemodynamic monitoring

1 What is a Swan-Ganz catheter? A Swan-Ganz catheter is a soft, flexible catheter with an inflatable balloon at its tip that is used in right-sided heart catheterization. The balloon tip allows the catheter to float with the flow of blood from the great veins through the right-sided heart chambers and into the pulmonary artery (PA) before wedging in a distal branch of the PA. 2…

Cardiac computed tomography

1 What are the contraindications for cardiac computed tomography? An inability to remain still, hold one’s breath, or follow instructions are relative contraindications to coronary computed tomography angiography (CTA). Anaphylactic reaction to intravenous iodinated contrast is considered an absolute contraindication, though less severe allergic reactions may be acceptable if the patient has been adequately premedicated, usually with a combination of intravenous (IV) or oral diphenhydramine and…

Cardiac magnetic resonance imaging

1 How does cardiac magnetic resonance imaging produce images? Cardiac magnetic resonance (CMR) uses a strong magnet 1.5 to 3.0 Tesla (equivalent to 30,000–60,000 times the strength of the earth’s magnetic field), radiofrequency pulses, and gradient magnetic fields to obtain images of the heart. When placed in the bore of a magnet, positively charged protons, mainly from water, are aligned in the direction of the magnetic…

Cardiac positron emission tomography

1 What is positron emission tomography? A positron, as its name implies, is a positively charged particle that is ejected from the nucleus of an unstable atom. It is identical in mass to an electron. Strictly speaking it is “antimatter,” and very shortly after leaving the nucleus, it collides with an electron in what is called an annihilation reaction. This reaction generates two 511-keV gamma photons…

Nuclear cardiology

1 What is nuclear cardiology? Nuclear cardiology is a field of cardiology that uses radioisotopes to assess myocardial perfusion and myocardial function in different clinical settings, as well as radionuclide angiography and metabolic and receptor imaging. 2 What is myocardial perfusion imaging? Myocardial perfusion imaging (MPI) is a noninvasive imaging method that utilizes radioisotopes to assess regional myocardial blood flow, function, and viability. MPI is used…

Echocardiography

1 How does echocardiography work? Echocardiography encompasses a group of applications using ultrasound to interrogate cardiac structures. Ultrasound technology utilizes acoustic (sound) waves, which are pulsatile pressure phenomena that travel through a transmission medium such as tissue. Like other waveforms, ultrasound can be characterized by frequency (the periodicity or number of cycles per second), wavelength (length of a single cycle), velocity, and amplitude (power or intensity).…

Ambulatory ECG monitors

1 What are the major indications for ambulatory electrocardiography monitoring? Ambulatory electrocardiography (AECG) monitoring allows the noninvasive evaluation of a suspected arrhythmia during normal daily activities. It aids in the diagnosis, documentation of frequency, severity, length of episodes, and correlation of an arrhythmia with symptoms such as palpitations, lightheadedness, or overt syncope. AECG monitoring can be extremely helpful in excluding an arrhythmia as a cause for…