Cardiac Function, Heart Failure, & Circulatory Shock (Ch. 27)-- Definition First Flashcards
Exam 2
-
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
Types of Shock
Left Ventricular Heart Failure
d/t– HTN (hypertrophy), Myocardial Ischemia (ventricular remodeling)
- Diastolic failure
- LVEF > 50% (normal)
- ⇣ LV Compliance → Abnormal diastolic relaxation → Pulmonary edema
S/S– Dyspnea w/ exertion, Fatigue
Treatment– None
Heart Failure with Preserved Ejection Fraction (HFpEF)
-
Zone of hypoxic injury
- May progress to necrosis or return to normal
-
Zone of reversible ischemia
- May progress to necrosis or return to normal
-
Sudden severe chest pain
- Can radiate to neck, jack, arm, or epigastric region
- Sending of impending doom → death
- SOB
- Weakness
- N/V
- Diaphoresis
Monitoring–
-
EKG
- Assess for rhythm changes
- Continuous monitoring
- Vitals
- O2 levels
- Lab work
-
Troponin I
- Most specific
- Elevated 2-12 hrs. after damage
- Remains elevated 2-4 wks.
- Creatinine Phosphokinase-MB (CPK-MB)
- Not specific to the heart
- Elevates w/i 4-8 hrs.
- Peaks @ 24 hrs.
-
Troponin I
Myocardial Infarction Clinical Manifestations
Infection of the inner surface of the heart
Microbial agents w/i valves & endocardium → Vegetation & destruction of cardiac tissue
- High mortality rate
-
Staphylococcal infections
- Most common
-
Aortic & Mitral valves
- Most common
-
Acute
- Rapid onset
- Normal heart valves
-
Sub-acute
- Evolves slowly over months
- Underlying valve abnormality
- Life-threatening
d/t– Dental or surgical procedures, Illicit IV drug use, Valve or congenital abnormalities (⇡ risk)
Prevention– Prophylactic antibiotics (w/ dental or surgical procedure)
Infectious Endocarditis (IE)
Widespread Type I Hypersensitivity reaction → Vasodilation & Hypovolemia
Treatment– Epinephrine → Vasoconstriction, Bronchodilation, ⇡ CO & Contractility, ⇣ Histamine
TOP PRIORITY: Maintain airway
Anaphylactic Shock
Systemic Inflammatory Response System
Microvascular damage that causes clotting at all sites simultaneously
Inflammation → Endothelial injury → Clotting process repeats (steps 3-5) → All platelets & clotting factors used up → Uncontrolled bleeding
Disseminated Intravascular Coagulation (DIC)
Life-threatening compression of the heart d/t accumulation of fluid w/i pericardial sac
- Inflammation & pressure
-
Fluid displaces septum
- w/ inspiration
- ⇡ Intracardiac pressure
- ⇣ LV filling
- ⇣ SV
- ⇣ CO
-
Pulsus paradoxus
- 10 mmHg + decrease in SBP w/ inspiration
Cardiac Tamponade
Volume ejected from ventricle w/ each beat
Stroke Volume (mL/beat)
Short-term pericardial inflammation
- < 2 weeks
- Infectious or non-infectious
Acute Pericarditis
Left Ventricular Heart Failure
d/t– Damage to myocardial tissue (MI, chronic HTN)
- Systolic failure
- LVEF < 40%
- Dilation → ⇡ Preload → ⇣ Contractility
- Ventricular remodeling d/t–
- ⇡ SANS
- ⇡ RAAS
- ⇡ Inflammatory mediators
Heart Failure with Reduced Ejection Fraction (HFrEF)
Immune-mediated inflammatory response to group A streptococcal pharyngitis
- Affects heart, skin, & connective tissue
- Acute
- Inflammation of all 3 layers & valves
- Epicardium
- Myocardium
- Endocardium
-
History of streptococcal infection
- Inflammatory lesions
- Inflammation of all 3 layers & valves
- Recurrent phase
- Continued effects
- Chronic phase
- Permanent deformity of valves
- 10+ years after initial infection
Rheumatic Heart Disease/Rheumatic Fever
-
Ascites
- Fluid w/i abdomen
- Lower extremity edema
- Dyspnea w/ exertion
- Fatigue
Constrictive Pericarditis Clinical Manifestations
-
⇡ 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
Frank-Starling Mechanism
- Mitral valve stenosis (narrowing)
- Rheumatic carditis
-
Polyarthritis
- Most common
- Skin lesions
Rheumatic Heart Disease Clinical Manifestations
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
Ejection Fraction (EF)
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
Natriuretic Peptides
Goal: Control compensatory mechanisms
- First-line HFrEF treatment
-
Diuretics
- ⇣ Blood volume
-
ACE-Is
- ⇣ RAAS
-
Beta-Blockers
- ⇣ SANS
-
Diuretics
Heart Failure Pharmacological Treatments
Imbalance → Ischemia, Angina, MI, or sudden death
-
Supply
- Determinants:
-
Perfusion of blood to capillaries
- O2-carrying capacity of blood
- Hgb levels
- O2-carrying capacity of blood
-
Perfusion of blood to capillaries
- Determinants:
-
Demand
-
⇡ LV contractility → ⇡ O2 demand
- Systole
- ⇡ HR → ⇡ O2 demands & ⇣ Blood flow d/t ⇣ Filling time
-
⇡ LV pressure → ⇡ O2 demand & Coronary artery pressure
- d/t ⇡ Preload
- Water balloon effect
-
⇡ LV contractility → ⇡ O2 demand
Myocardial Oxygen Supply & Demand
Life-threatening complication of shock
Progressive dysfunction of two or more organ systems
d/t– Uncontrolled inflammatory response to severe injury/illness (sepsis, trauma, burns, major surgery…)
- Manifestations
- Dysfunction of–
- Respiratory organs
- Liver
- Kidneys
- GI organs
- Heart failure
- Dysfunction of–
Interventions– Support affected organs
Multiple Organ Dysfunction System (MODS)
Coronary blood flow doesn’t meet metabolic demands of heart
1st– Stable angina
2nd– Unstable angina → ACS
Prolonged– MI (STEMI or non-STEMI)
Myocardial Ischemia
Dilated LV w/ thin walls (“floppy”) → ⇣ Contractility → ⇡ Preload → Systolic dysfunction & HF
d/t– DM, MI, Alcoholism, Hyperthyroidism
Dilated (Congestive) Cardiomyopathy
- Acute Lung Injury (ALI)/Acute Respiratory Distress Syndrome (ARDS)
- Sudden onset of profound dyspnea
- Hypoxemia refractory to supplemental O2
- Potentially fatal
- Acute Kidney Injury (AKI)
- ⇣ Renal perfusion
- Disseminated Intravascular Coagulation (DIC)
- Multiple Organ Dysfunction Syndrome (MODS)
Complications of Shock
-
Chest pain
- ⇡ w/ breathing, coughing, swallowing, & positional changes
- ⇣ w/ sitting upright & leaning forward
- Pericardial friction rub
- EKG changes
- ⇣ CRP
- C-reactive protein
-
⇣ ESR
- Erythrocyte sedimentation rate
Treatment– NSAIDs, Antimicrobials
Acute Pericarditis Clinical Manifestations
Acute loss of blood volume (600-900 mLs)
d/t– Hemorrhage, Burns (⇣ plasma), Loss of GI fluid (N/V)
- Compensation
- ⇡ SANS
- ⇡ RAAS
- ⇡ ADH/Vasopressin
- Nursing interventions
- STOP blood loss
- Replace lost volume
Hypovolemic 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
Cardiogenic Shock
Dysfunction @ any valve → Heart Failure (HF)
-
Stenosis
- Narrowing/stiffness of valve
- Impaired valvular opening
- ⇡ Resistance → ⇡ Myocardial work & ⇡ Heart chamber volume
- Narrowing/stiffness of valve
-
Incompetent/Regurgitant Valve
- “Floppy”
- Impaired valvular closing
- Backflow of blood
- “Floppy”
Valvular Heart Disease
⇡ Afterload → Hypertrophy of myocytes to compensate for ⇡ workload
Diastolic dysfunction → Systolic dysfunction
d/t– HTN, Aortic stenosis (Narrowing of aortic opening)
Hypertensive (Valvular) Hypertrophic Cardiomyopathy