Orthostatic Disorders of the Circulation: Mechanisms, Manifestations, and Treatment

ISBN-13: 9781468489644 / Angielski / Miękka / 2012 / 286 str.

David H. P. Streeten

Opis

Most of us spend at least two-thirds of our lives either sitting or standing. It is somewhat surprising, therefore, to find not a single book devoted to disorders caused by derangements of the normal physiological adjustments to changes in posture. In fact, until very recently, medical students have not even been advised to measure the blood pressure and heart rate in the upright posture as part of the routine physical examination. Although Bradbury and Eggleston first described orthostatic hypotension as a consequence of autonomic insufficiency in 1925, interest in orthostatic disorders has been slow to develop in the subsequent years. It is well known that the change from recumbency to the standing posture stimulates neurological, endocrine, and cardiovascular adjustments that ensure maintenance of a normal circulation despite the effects of gravitational forces. The mechanisms of these physiological responses to orthostasis have been stud- ied by many investigators. Some of the defects to which antigravitational com- pensatory mechanisms are subject, such as postural hypotension resulting from autonomic failure, have been studied intensively and have become part of the general knowledge of most medical practitioners. Other orthostatic disorders- such as various other postural abnormalities of blood pressure control, and orthostatic edema-have received far less attention and have been unable to compete with the more dramatic and life-threatening ailments of humankind for a place in our standard medical texts. These disorders often give rise to distressing symptoms and may lead to severe impairment of health.

Spis treści

1 Physiology of the Microcirculation.- 1.1. Control of the Peripheral Vasculature.- 1.1.1. Sympathetic Innervation.- 1.1.2. Humoral Agents and Local Tissue Metabolites.- 1.2. Physiological Requirements Imposed by Orthostasis.- 1.3. Orthostatic Circulatory Adjustments: Neurohumoral Mechanisms.- 1.3.1. Catecholamine Responses.- 1.3.2. Changes in the Renin-Angiotensin-Aldosterone System.- 1.3.3. Other Physiological Changes in the Erect Posture.- 1.4. Disorders of the Peripheral Circulation.- 1.5. Orthostatic Disorders of the Circulation.- 1.6. Summary.- 2 Orthostatic Edema: Definition and Pathogenesis.- 2.1. Definition of Orthostatic Edema.- 2.2. General Mechanisms of Edema Formation.- 2.2.1. Increased Capillary Hydrostatic Pressure.- 2.2.2. Reduced Plasma Protein Oncotic Pressure.- 2.2.3. Pathologically Leaky Capillaries.- 2.2.4. Tissue Pressure Changes.- 2.2.5. Lymphatic Obstruction.- 2.3. Pathogenesis of Orthostatic Edema.- 2.3.1. Role of Posture in the Pathogenesis of Edema.- 2.3.2. Mechanisms of Orthostasis-Induced Fluid Retention.- 2.3.3. Summary of Pathogenesis.- 2.3.4. How Does Orthostasis Trigger the Abnormal Responses in Patients with Orthostatic Sodium Retention?.- 2.3.5. Cause of Excessive Orthostatic Intravascular Pooling.- 2.4. Summary.- 3 Orthostatic Edema: Clinical Features.- 3.1. Gender, Age, and Prevalence.- 3.1.1. In Women.- 3.1.2. In Men.- 3.1.3. Age of Onset.- 3.1.4. Distribution and Prevalence.- 3.2. Symptoms and Signs.- 3.2.1. Evidence of Fluid Accumulation.- 3.2.2. Nocturia.- 3.2.3. Symptoms Resulting from the Edema.- 3.2.4. Intracranial Symptoms.- 3.2.5. Cardiovascular Features.- 3.2.6. Other Clinical Features.- 3.3. Factors That Aggravate Orthostatic Edema.- 3.3.1. Menstruation.- 3.3.2. Oral Estrogen Therapy.- 3.3.3. Pregnancy.- 3.3.4. Environmental Heat.- 3.4. Laboratory Findings.- 3.5. Summary.- 4 Orthostatic Edema: Diagnosis.- 4.1. Exclusion of Known Types of Edema.- 4.1.1. Congestive Heart Failure.- 4.1.2. Renal Edema.- 4.1.3. Hepatic Disease.- 4.1.4. Other Generalized Disorders.- 4.1.5. Local Causes of Edema.- 4.1.6. Capillary Leak Syndrome.- 4.2. Positive Diagnosis of Orthostatic Edema.- 4.2.1. History.- 4.2.2. Screening Test.- 4.2.3. Definitive Tests.- 4.3. Summary.- 5 Orthostatic Edema: Treatment and Prognosis.- 5.1. General Aspects.- 5.2. Control of Posture.- 5.3. Dietary and Fluid Restrictions.- 5.4. Conventional Diuretics.- 5.5. Treatment of Potassium Depletion.- 5.5.1. Potassium-Sparing Diuretics.- 5.5.2. Potassium Supplements.- 5.6. Elastic Garments and Stockings.- 5.7. Dopamine Agonists.- 5.8. Converting Enzyme Inhibitors: Captopril.- 5.9. Vasoconstrictors.- 5.9.1. Ephedrine.- 5.9.2. Amphetamines.- 5.9.3. Midodrine.- 5.9.4. Mechanism of Action of Vasoconstrictors in Orthostatic Edema.- 5.9.5. Side Effects of Sympathomimetic Amines.- 5.9.6. Long-Term Administration of Sympathomimetic Agents.- 5.10. Summary of Therapeutic Program.- 5.11. Summary.- 6 Orthostatic Disorders of Blood Pressure Control: Definitions and Classification.- 6.1. Technique of Blood Pressure Measurement in the Upright Posture.- 6.2. Orthostatic Blood Pressure and Heart Rate Changes: Normal Limits.- 6.3. Definable Disorders of Blood Pressure and Heart Rate Control.- 6.3.1. Orthostatic Arterial Anemia.- 6.3.2. Neurocirculatory Asthenia.- 6.4. Classification of Orthostatic Disorders of Blood Pressure Control.- 6.4.1. Role of the Autonomic Nervous System.- 6.4.2. Heart Rate Changes.- 6.4.3. Effects of Adrenocortical Insufficiency.- 6.4.4. Excessive Orthostatic Rise in Diastolic Blood Pressure.- 6.4.5. Types of Orthostatic Blood Pressure Disorders.- 6.5. Summary.- 7 Orthostatic Disorders of Blood Pressure Control: Pathocenesis.- 7.1. Orthostatic Hypotension.- 7.1.1. Autonomic Insufficiency.- 7.1.2. Hyperadrenergic Postural Hypotension.- 7.2. Orthostatic Hypertension and Other Types of Orthostatic Blood Pressure Disorders.- 7.3. Causes of Orthostatic Blood Pressure Disorders.- 7.4. Pathogenesis of Orthostatic Blood Pressure Disorders Associated with Intact Autonomic Function.- 7.4.1. Effects of Changes in Blood Volume Induced by Venesection.- 7.4.2. Evidence of Excessive Gravitational Pooling of Blood.- 7.4.3. Effects of Posture on Cardiac Filling.- 7.4.4. Effects of Posture on Cardiac Output.- 7.4.5. Postural Changes in Plasma Norepinephrine Concentration.- 7.4.6. Blood Kinin Concentration.- 7.4.7. Potential Role of Insulin.- 7.5. Conclusions.- 7.6. Summary.- 8 Orthostatic Disorders of Blood Pressure Control: Clinical Features.- 8.1. Frequency of Main Symptoms.- 8.2. Intracranial Features.- 8.2.1. Lightheadedness and Blurred Vision.- 8.2.2. Syncope.- 8.2.3. Convulsive Seizures.- 8.2.4. Orthostatic Hemiplegia.- 8.2.5. Headaches.- 8.2.6. Symptoms of Carotid or Basilar Artery Insufficiency.- 8.3. Other Clinical Features.- 8.3.1. Fatigue and Weakness.- 8.3.2. Nausea.- 8.3.3. Palpitations, Flushing Spells, and Excessive Sweating.- 8.3.4. Nocturia.- 8.3.5. Aggravation by Heat.- 8.3.6. Edema.- 8.3.7. Cyanosis of the Legs.- 8.3.8. Changes in Blood Pressure and Heart Rate.- 8.3.9. Cardiac Disorders.- 8.3.10. Plasma Volume Changes.- 8.3.11. Other Features of Autonomic Failure.- 8.4. Summary.- 9 Orthostatic Disorders of Blood Pressure Control: Prevalence and Diagnosis.- 9.1. Prevalence.- 9.2. Sex Incidence and Age of Onset.- 9.3. Hereditary Factor.- 9.4. Diagnosis of Orthostatic Blood Pressure Derangements.- 9.4.1. Orthostatic Hypotension.- 9.4.2. Differentiation of Central from Peripheral Autonomic Failure.- 9.4.3. Venous Pooling Syndrome.- 9.5. Summary.- 10 Orthostatic Disorders of Blood Pressure Control: Treatment and Prognosis.- 10.1. Treatment.- 10.1.1. Physical Compression of the Lower Limbs and Abdomen…..- 10.1.2. Vasoconstricting Drugs.- 10.1.3. ?-Adrenergic Antagonists.- 10.1.4. Fludrocortisone and Other Volume Expanders.- 10.1.5. Prostaglandin Synthetase Antagonists.- 10.1.6. Vasopressin.- 10.1.7. Atrial Pacemakers.- 10.1.8. Other Measures.- 10.1.9. Treatment of Orthostatic Hypertension.- 10.2. Prognosis.- 10.3. Summary.- Appendix I Clinical and Laboratory Data Obtained in 169 Patients with Orthostatic and Nonorthostatic Edema.- Appendix II Clinical and Laboratory Data Obtained in 159 Patients with Orthostatic Blood Pressure Disorders.- References.