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Giới thiệu
Heart failure is a clinical syndrome that is due to a structural or functional cardiac abnormality that impairs the ability of the ventricle to fill with or eject blood in order to deliver oxygen (O2) at a rate commensurate with the requirements of the metabolizing tissues in spite of normal filling pressures or only at the expense of elevated filling pressures. This is corroborated by objective evidence of cardiogenic, pulmonary, or systemic congestion and/or elevated levels of natriuretic peptides. This is characterized by either left ventricular (LV) hypertrophy or dilation or both.
Acute heart failure is a rapid or gradual onset of or change in the signs and/or symptoms of heart failure and arises as a result of acute cardiac function deterioration in previously stable patients with heart failure or may also be the first presentation of heart failure (de novo heart failure). Acute heart failure arising from decompensation of chronic heart failure is a slow and progressive deterioration and is associated with arrhythmia, uncontrolled hypertension, infection, and non-compliance with therapy and diet. The cardiac dysfunction may be related to ischemia, arrhythmia, valvular abnormalities, pericardial disease, myocarditis, cardiomyopathy, increased filling pressure, or elevated systemic resistance.
Dịch tễ học
Heart failure affects more than 60 million individuals globally. The prevalence ranges between 1-2% in the general adult population. The incidence of heart failure increases with age and is higher in males than in females.
The prevalence estimates of heart failure in Asia range between 1.3% and 6.7%. In Asia, the prevalence of heart failure with preserved ejection fraction (HFpEF) is higher compared with the Western countries and may be due to enhanced treatment and prevention of ischemic heart disease. In Southeast Asia, the lean diabetic phenotype makes up 20% of all heart failure cases and is associated with higher rates of all-cause mortality and hospitalization. The age-standardized prevalence of heart failure per 100,000 population was highest in East Asia and lowest in South Asia.
Sinh lý bệnh
Heart failure results from systolic dysfunction due to impaired cardiac contractility, and diastolic dysfunction due to impaired ventricular relaxation and compliance which limit effective cardiac filling.
Cardiac injury stimulates cellular, structural, and neurohumoral modulations influencing cell function leading to activation of the sympathoadrenergic and renin-angiotensin-aldosterone system (RAAS) and resulting to adaptive mechanisms accompanied by volume overload, tachycardia, dyspnea, and further deterioration of the cellular function.
Catecholamines increase intracellular calcium thereby increasing contractility but increases myocardial O2 demand in the long run which can lead to life-threatening arrhythmias and activation of signaling pathways of hypertrophy and cell death resulting to further cardiac function deterioration. Permanent activation of the neurohumoral system also affects cell expression and cell function (eg stretch-induced force generation, frequency-induced force generation, interstitial and structural cell-interaction).
Nguyên nhân
The causes of acute heart failure are acute coronary syndrome or its complications (eg rupture of interventricular septum, right ventricular infarction, valvular heart disease, mitral valve chordal rupture, acute mitral regurgitation); hypertensive crisis or severe and uncontrolled hypertension; tachyarrhythmia (eg atrial fibrillation, ventricular tachycardia); severe bradycardia or conduction abnormalities; pulmonary embolism; infection (eg infective endocarditis, viral myocarditis, pneumonia, sepsis); pericardial or cardiac tamponade; aortic dissection; surgery and perioperative problems; peripartum or stress-related cardiomyopathy; chronic obstructive pulmonary disease (COPD) exacerbation; cerebrovascular insult; worsening renal failure; electrolyte disturbances; non-compliance to diet or drug therapy; medications (nonsteroidal anti-inflammatory drugs [NSAIDs]; steroids; cardiotoxic chemotherapeutics; negative inotropic agents, drugs that increase fluid retention, Clozapine); high output states (eg severe anemia, thyrotoxicosis, large atrioventricular shunts/malformations); fluid overload (eg volume overload causing pulmonary edema in acute kidney injury, iatrogenic causes); and toxic substances (recreational drugs, alcohol, radiotherapy).
Yếu tố nguy cơ
The risk factors for heart failure are increasing age, male sex, coronary artery disease, atherosclerotic disease, hypertension, diabetes mellitus, metabolic syndrome, obesity, smoking, alcohol use, and exposure to drugs (eg cancer chemotherapies) or toxins with cardiotoxicity. Inflammation also plays a key role in the development of heart failure. Socioeconomic status is also a risk factor for heart failure due to poor diet, smoking, physical inactivity, and non-adherence to medications.
Phân loại
Clinical Conditions
Patients with acute heart failure may present in one of the
following clinical categories:
Worsening or Decompensated Heart Failure
Usually, there is a history of progressive worsening of chronic heart
failure on treatment and evidence of systemic and pulmonary congestion and
increased intraventricular pressure. Hypotension on admission is associated with
a poor prognosis.
Pulmonary Edema
Heart Failure - Acute_Disease BackgroundPatients with pulmonary edema present with severe respiratory distress, tachypnea, orthopnea, and rales over the lung fields. Arterial O2 saturation is usually <90% on room air prior to O2 therapy. This diagnosis is confirmed by chest radiography.
Isolated Right Heart Failure
Patients with isolated right heart failure present with symptoms and signs of right-sided volume overload. This is a low-output syndrome in the absence of pulmonary congestion with elevated jugular venous pressure, with or without hepatomegaly and low left ventricular filling pressures. Systolic blood pressure and cardiac output are low, and right ventricular end-diastolic pressure is increased.
Cardiogenic Shock
In cardiogenic shock, there is tissue hypoperfusion induced by heart failure after adequate correction of preload and major arrhythmia. This is characterized by hypotension (SBP <90 mmHg, mean arterial pressure <60 mmHg, or a decrease of >30 mmHg from baseline systolic blood pressure) and absent or low urine output of <0.5 mL/kg/hr. Rhythm disturbance is common. Pulmonary congestion and organ hypoperfusion develop rapidly. There is a continuum from low cardiac output syndrome to cardiogenic shock.
Hypertensive Heart Failure
There are signs and symptoms of heart failure accompanied by high blood pressure and preserved left ventricular function (heart failure with a preserved ejection fraction). There is evidence of increased sympathetic tone with tachycardia and vasoconstriction. They may be mildly hypervolemic or euvolemic with signs of pulmonary congestion without signs of systemic congestion. There is a rapid response to appropriate treatment and a low hospital mortality.
Acute Coronary Syndrome and Heart Failure
Some patients with acute coronary syndrome present with symptoms and signs of heart failure. The episodes of heart failure are associated with or precipitated by arrhythmia. Patients are managed according to the acute coronary syndrome (ACS) guidelines.
Acute Mechanical Causes
Acute mechanical causes are conditions that include acute incompetence of the native or prosthetic valve due to endocarditis, aortic dissection or thrombosis, cardiac intervention, chest trauma, or acute coronary syndrome complicated by the rupture of the myocardium such as acute mitral regurgitation, free wall rupture, or ventricular septal defect.