Cardiac Function, Heart Failure, & Circulatory Shock (Ch. 27)-- Term First Flashcards
Exam 2
Coronary Artery Disease (CAD)
Occlusion or stenosis of coronary arteries → Imbalance b/w coronary blood supply and myocardial O2 & nutrient demand
d/t– Atherosclerosis (most common)
Heart Failure Clinical Manifestations
- Fatigue & weakness
- ⇣ CO
- Cognitive impairment
-
d/t ⇣ brain perfusion
- Confusion
- Memory loss
- Restlessness
- Anxiety
- Insomnia
-
d/t ⇣ brain perfusion
- Cachexia & malnutrition
-
Ascites & tissue wasting w/ end-stage HF
- ⇣ food intake d/t depression, illness, GI congestion
-
Ascites & tissue wasting w/ end-stage HF
- Sudden cardiac death
- d/t ventricular tachycardia or fibrillation
Constrictive Pericarditis Clinical Manifestations
-
Ascites
- Fluid w/i abdomen
- Lower extremity edema
- Dyspnea w/ exertion
- Fatigue
Frank-Starling Mechanism
-
⇡ Preload = ⇡ SV
- The further you stretch a rubberband, the harder it snaps back
- Inotropy (⇡ SANS)
-
⇡ Contractility
- Curve shifts up & L
-
⇡ Contractility
- Failure
- ⇣ Contractility
- Curve shifts down & R
- ⇣ Contractility
Cardiomyopathies
Inappropriate ventricular hypertrophy or dilation
d/t– Genetics, Ischemia, MI (ventricular remodeling), Idiopathic
Acute Pericarditis
Short-term pericardial inflammation
- < 2 weeks
- Infectious or non-infectious
Contractility
Ability of myocardial tissue to contract
⇣ d/t– MI (most common), ⇣ O2 supply
MI Treatment (STEMI)
- Pharmacologic therapy
-
ASA (chewed)
- ⇣ Platelet aggregation
-
Morphine
- Pain
- Vasodilation
-
Sublingual Nitroglycerin (MONA)
- Vasodilation
-
ASA (chewed)
- Supplemental O2
- Active STEMI (EKG verfied)
- Percutaneous coronary intervention (PCI)– w/i 60 min.
- Cath lab
- Coronary artery bypass graft (CABG)
- Fibrinolysis– w/i 30 min.
- Tissue plasminogen activator (tPA)
- “Clot buster”
- If no cath lab
- Tissue plasminogen activator (tPA)
- Percutaneous coronary intervention (PCI)– w/i 60 min.
Constrictive Pericarditis
Development of a constrictive membrane around the heart
- Scar tissue b/w visceral & parietal layers
- Fixed CO
- Regardless of contractility
d/t– Chronic inflammation, Cardiac surgery
Infection & Removal of pericardial sac → Remodeling
Pericardial Effusion
Accumulation of fluid in pericardial cavity → Cardiac tamponade
d/t– Inflammation or infection (CA, cardiac surgery, trauma…)
Treatment– Removal of fluid, Percardiocentesis (needle aspiration)
Ejection Fraction (EF)
Proportion of blood pumped out of ventricle with each beat
Measured w/ echocardiogram
LVEF (%) = (SV/EDV)100
LVEF= Left ventricular ejection fraction (normal 55-75%)
SV= Stroke volume
EDV= End diastolic volume
Shock Response
-
Anaerobic metabolism
- Lactic acid accumulation
- ⇣ ATP → Na+/K+ ATPase pump failure
- ⇡ Membrane permeability → Cell swells & bursts
-
Compensatory mechanisms (Short-term)
-
⇡ SANS
- ⇡ HR
- Vasoconstriction
- ⇡ Renin
-
⇡ Angiotensin II
- Vasoconstriction
- ⇡ Blood volume
-
⇡ Aldosterone
- ⇡ Blood volume
-
⇡ Angiotensin II
-
⇡ SANS
Objective Evidence of Cardiogenic Systemic or Pulmonary Congestion
- Non-Invasive
-
Chest x-ray
- Fluid congestion
- White cotton candy-like appearance
- Fluid congestion
-
Echocardiogram
- Elevated filling pressures
-
Chest x-ray
- Invasive
- R heart or pulmonary artery catheterization
Myocardial Infarction
Prolonged ischemia causes irreversible damage to the heart muscle (myocyte necrosis)
- Myocyte injury → death
- Structural & functional changes of cardiomyocytes (permanent cells)
- Adverse myocardial remodeling
- Fibrosis of myocardium
- Adverse myocardial remodeling
Natriuretic Peptides
Neurohumoral compensatory mechanism of HF
Diuresis & Natriuresis (⇡ GFR) → ⇣ Fluid volume → ⇣ Workload of the heart
Inhibit SANS, RAAS, ADH/Vasopressin, & CNS thirst/salt appetite signaling
- Atrial natriuretic peptide (ANP)
- Released from atrium
- d/t atrial stretch, pressure, or fluid overload
- Released from atrium
- B-type natriuretic peptide (BNP)
- Released from ventricles
- d/t increased ventricular pressure or fluid overload
- Measured clinically
- Released from ventricles
Myocardial Infarction Types
The extent of necrosis determines EKG tracing differences
-
STEMI
-
ST-segment elevation
-
Full necrosis of one area
- Blocked conduction
- “Tombstone” = MI
-
Full necrosis of one area
-
ST-segment elevation
-
Non-STEMI
- Non-ST segment elevation
-
ST-segment depression
-
Partial necrosis
- ⇣ Conduction
-
Partial necrosis
- OR T inversion
-
ST-segment depression
- May indicate ischemia
- Does not always = MI
- Non-ST segment elevation
Cardiac Catheterization
Assessment of coronary blood flow & perfusion
- Done under x-ray
-
Invasive, sterile procedure
- Catheter placed in femoral or brachial artery or vein
- Assess blood flow through the heart
-
Angioplasty
- Inflate balloon → Improved blood flow through arteries
-
Stent
- Metal mesh coil keeps arteries open
- Heart tissue biopsy
- Fractional flow reserve
- Measurement of arterial blockage
- Intravascular ultrasound (IVUS)
- Blood vessel lumen measurement
Atherosclerosis
- Impaired contractility
-
Deprivation of myocardial O2 & nutrients
- Mismatch b/w supply & demand
- Leads to CAD
Types of Shock
-
Hypovolemic
- Acute blood loss (15% or more)
-
Cardiogenic
- Heart fails to pump sufficient amount of blood
-
Distributive (Normovolemic)
- Capacity of vascular compartment expands
- Neurogenic
- Anaphylactic
- Septic
- Capacity of vascular compartment expands
Rheumatic Heart Disease Clinical Manifestations
- Mitral valve stenosis (narrowing)
- Rheumatic carditis
-
Polyarthritis
- Most common
- Skin lesions
Myocardial Ischemia
Coronary blood flow doesn’t meet metabolic demands of heart
1st– Stable angina
2nd– Unstable angina → ACS
Prolonged– MI (STEMI or non-STEMI)
Acute Coronary Syndrome
Sudden coronary obstruction d/t thrombosis formation b/c of an unstable lesion
d/t– Unstable angina, MI (STEMI or non-STEMI)
- Complications
- Dysrhythmias
- CHF
- Sudden death
Types of Heart Failure
- Can lead to each other
-
Left ventricular failure
- HFpEF
- HFrEF
- Right ventricular failure
- Both ventricles fail
Electrocardiogram
Assessment of coronary blood flow & perfusion
- Measure of electrical conduction through the heart
- Impacted by
- Temperature
- Stress
- Full
- 12 leads
- Monitor
- 3-5 leads
Stroke Volume (mL/beat)
Volume ejected from ventricle w/ each beat
Aortic Valve Disorders
- Stenosis
- ⇡ Afterload → LV Hypertrophy → HF
- Regurgitation
- ⇡ Preload → ⇡ Size/Dilation of LV → ⇡ SV → HF
Cardiogenic Shock
Heart fails to pump adequate amount of blood to meet O2 demands
d/t– MI w/ LV failure
-
⇣ CO
- Tissue hypoxia
- Normal vascular volume
- Compensatory mechanisms
- WORSEN situation
- ⇡ SANS
- ⇡ HR
- ⇡ Preload
- ⇡ RAAS
- ⇡ Blood volume
- ⇡ ADH/Vasopressin
- ⇡ Blood volume