1 / 74

Farmacología Cardiovascular

Farmacología Cardiovascular . SISTEMA CIRCULATORIO: FUNCIONES PRINCIPALES. Transportar y distribuir sustancias esenciales a los tejidos Remover desechos metabólicos Ajustar la provisión de oxígeno y nutrientes en diferentes estados metabólicos Regulación de la temperatura corporal

rock
Télécharger la présentation

Farmacología Cardiovascular

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Farmacología Cardiovascular

  2. SISTEMA CIRCULATORIO: FUNCIONES PRINCIPALES • Transportar y distribuir sustancias esenciales a los tejidos • Remover desechos metabólicos • Ajustar la provisión de oxígeno y nutrientes en diferentes estados metabólicos • Regulación de la temperatura corporal • Comunicación humoral

  3. Un sistema complicado

  4. Que se puede simplificar SERIES AND PARALLEL CIRCUITS

  5. CICLO CARDIACO

  6. 0 0 mv mv -80mv -80mv 0 mv -80mv Potencial de acción cardíaco ATRIUM VENTRICLE SA NODE time

  7. Conductacias del PA cardíaco

  8. Fast K reopens Slow K opens Fast K closes ("Delayed rectifier") Corrientes y PA cardíaco

  9. Del PA al ECG

  10. AV NODE AND AV BLOCKS FOCUS ON N REGION ECG NORMAL 1ST DEGREE PROLONGUED AV CONDUCTION TIME 2ND DEGREE 1/2 ATRIAL IMPULSES CONDUCTED TO VENTRICLES 3RD DEGREE VAGAL MEDIATION IN N REGION/COMPLETE BLOCK

  11. ENFERMEDAD CARDÍACA • Cardiovascular disease is the major cause of death • Cardiovascular function based on • Cardiac pumping ability • Pace-making electrical signals • Force of contraction • Height of ventricle discharge pressure • Integrity of vasculature • Presence of blockage • Muscular tone/structural integrity • Pressure drop needed to move blood to and through capillary beds • Blood volume/composition • Water, electrolyte, iron balances • Lipid and protein composition

  12. Patologías cardiovasculares que requieren farmacoterapia • Hipertensión • Arritmia • Falla cardíaca • Trastornos de flujo vascular

  13. I. Background to Hypertension -Regulation of Blood Pressure • Arterial blood pressure due to combination of cardiac output (CO) and total peripheral resistance (TPR) • CO – regulated by heart rate and stroke volume (CO = HR x SV) • TPR function of • Viscosity of blood (hematocrit) • Length of blood vessels • Blood vessel luminal diameter (especially precapillary arterioles)

  14. Cardiac Output • Heart rate • Function of • sympathetic, vagal nervous activity • Neuro-hormonal substances • 1° angiotensin II • 2º vasopression (anti-diuretic hormone = ADH) • Stroke volume • Function of • Venous return (function of venous tone [contractile state] and circulating blood (vascular) volume) • Venous tone function of sympathetic activity (α1, α2 receptors) • Vascular volume depends on • Intake of fluids (thirst) • Output of fluids (urine, sweat, etc) • Distribution of fluids (Starling’s law) • Myocardial contractility (MC proportional to sympathetic tone [β1 receptors])

  15. Characteristics of some adrenoceptors (sympathetic nerves) Tissues and effects receptors

  16. Autonomic Regulation of the Heart • Heart Rate • Parasympathetic input via vagus nerve causes decrease in HR (dominates) • Sympathetic input to sino-atrial node causes increase in HR (usually minor) • Heart contractility • Increased by sympathetic activity causing release of epinephrine, norepinephrine from adrenal gland

  17. Hipertensión

  18. Antihypertensive Classes • diuretics • beta blockers • angiotensin-converting enzyme (ACE) inhibitors • calcium channel blockers • vasodilators

  19. Alpha1 Blockers Stimulate alpha1 receptors -> hypertension Block alpha1 receptors -> hypotension • doxazosin (Cardura®) • prazosin (Minipress®) • terazosin (Hytrin®)

  20. Central Acting Adrenergics Stimulate alpha2 receptors inhibit alpha1 stimulation hypotension • clonidine (Catapress®) • methyldopa (Aldomet®)

  21. Peripheral Acting Adrenergics reserpine (Serpalan®) inhibits the release of NE diminishes NE stores leads to hypotension Prominent side effect of depression also diminishes seratonin

  22. Adrenergic Side Effects Common dry mouth, drowsiness, sedation & constipation orthostatic hypotension Less common headache, sleep disturbances, nausea, rash & palpitations

  23. Sistema renina-angiotensina

  24. ACE Inhibitors RAAS Angiotensin I ACE Angiotensin II 1. potent vasoconstrictor - increases BP 2. stimulates Aldosterone - Na+ & H2O reabsorbtion .

  25. Renin-Angiotensin Aldosterone System Angiotensin II = vasoconstrictor Constricts blood vessels & increases BP Increases SVR or afterload ACE-I blocks these effects decreasing SVR & afterload

  26. ACE Inhibitors Aldosterone secreted from adrenal glands cause sodium & water reabsorption Increase blood volume Increase preload ACE-I blocks this and decreases preload

  27. Angiotensin Converting Enzyme Inhibitors captopril (Capoten®) enalapril (Vasotec®) lisinopril (Prinivil® & Zestril®) quinapril (Accupril®) ramipril (Altace®) benazepril (Lotensin®) fosinopril (Monopril®)

  28. Calcium Channel Blockers • Used for: • Angina • Tachycardias • Hypertension

  29. Antagonistas de calcio como vasodilatadores

  30. Calcium Channel Blockers diltiazem (Cardizem®) verapamil (Calan®, Isoptin®) nifedipine (Procardia®, Adalat®)

  31. CCB Site of Action diltiazem & verapamil nifedipine (and other dihydropyridines)

  32. CCB Action • diltiazem & verapamil • decrease automaticity & conduction in SA & AV nodes • decrease myocardial contractility • decreased smooth muscle tone • decreased PVR • nifedipine • decreased smooth muscle tone • decreased PVR

  33. Side Effects of CCBs • Cardiovascular • hypotension, palpitations & tachycardia • Gastrointestinal • constipation & nausea • Other • rash, flushing & peripheral edema

  34. Diuretics Thiazides: chlorothiazide (Diuril®) & hydrochlorothiazide (HCTZ®, HydroDIURIL®) Loop Diuretics furosemide (Lasix®), bumetanide (Bumex®) Potassium Sparing Diuretics spironolactone (Aldactone®)

  35. Diuretic Site of Action . Distal tubule proximal tubule Collecting duct loop of Henle

  36. Mechanism • Water follows Na+ • 20-25% of all Na+ is reabsorbed into the blood stream in the loop of Henle • 5-10% in distal tubule & 3% in collecting ducts • If it can not be absorbed it is excreted with the urine •  Blood volume =  preload !

  37. Side Effects of Diuretics • electrolyte losses [Na+ & K+ ] • fluid losses [dehydration] • myalgia • N/V/D • dizziness • hyperglycemia

  38. Vasodilators • diazoxide [Hyperstat®] • hydralazine [Apresoline®] • minoxidil [Loniten®] • sodium Nitroprusside [Nipride®]

  39. Mechanism of Vasodilators • Directly relaxes arteriole smooth muscle • Decrease SVR = decrease afterload

  40. Nitratos como vasodilatadores

  41. Side Effects of Vasodilators • hydralazine (Apresoline®) • Reflex tachycardia • sodium nitroprusside (Nipride®) • Cyanide toxicity in renal failure • CNS toxicity = agitation, hallucinations, etc.

  42. II. Background to Arrhythmia - Rhythm of the Heart • Human heart is four-chambered • Chambers need to contract sequentially (atria, then ventricles) and in synchronicity • Also need relaxation between contractions to allow refilling of chambers • Above controlled electrically (Purkinje fibers allow rapid, organized spread of activation)

More Related