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SEARCH RESULTS FOR: Stable-Angina

angor-instable-angine-de-poitrine-pathogenese-et-observations-cliniques

angor-instable-angine-de-poitrine-pathogenese-et-observations-cliniques

angine-de-poitrine-angor-stable-pathogenese-et-decouvertes-cliniques

Angine de Poitrine/Angor Stable: Pathogénèse et Découvertes Cliniques

unstable-angina-pathogenesis-and-clinical-findings

Unstable Angina/Unstable Angina Pectoris: Pathogenesis and clinical findings Primary cause:
Secondary causes:
Coronary artery vasospasm - primary or drug induced (Ex: cocaine, triptans)
Coagulopathy
(Ex: antiphospholipid antibody syndrome)
Vasculitic syndromes (Ex: Takayasu arteritis)
Authors: Marisa Vigna Ryan Wilkie Yan Yu* Reviewers: Julena Foglia Davis Maclean Mehul Gupta Andrew Grant* * MD at time of publication
  Atherosclerosis
Fatty plaque accumulates inside the intimal walls of arteries Coronary arterial atherosclerotic plaque rupture or erosion
Plaque disruption exposes subendothelial components of damaged vessel wall to platelets, initiating the coagulation cascade and platelet adhesion
Aggregation of platelets results in the formation of a thrombus Thrombus partially occludes blood flow through a coronary artery âmyocardial blood supply
Congenital anomalies (Ex: myocardial bridge, anomalous coronary)
Spontaneous coronary artery dissection
Increased blood viscosity (Ex: polycythemia, thrombocytopenia)
Factors thatámyocardial (cardiac muscle) oxygen demand (Ex: tachycardia, hypotension, hypertension, anemia, exertion, stress)
Coronary embolism (Ex: A. Fib, endocarditis, prosthetic valve thrombus)
                   áheart rate, contractility, and/or wall tension ámyocardial oxygen demand
       Myocardial ischemia due to imbalance between blood supply and oxygen demand (insufficient blood/oxygen supply)
Unstable Angina/Unstable Angina Pectoris
Can be new onset angina; typically progressive in frequency, severity, or duration; can occur at rest
      Subtotal occlusion of a coronary arteryà
reduced, but continued, myocardial blood supply
Maintained perfusion means cardiomyocytes are still alive and thus do not leak troponin into bloodstream
Normal serum troponin
Diaphoresis
(sweating)
Since bloodflow occurs from epicardium to endocardium, myocardial ischemia is more
pronounced in the subendocardium (region furthest away from heart’s external surface)
Sufficient blood flow is maintained in regions superficial to the subendocardium, resulting in non-transmural (partial thickness) heart wall ischemia
Non-inferior wall ischemia triggers a predominantáin sympathetic nervous system activity, given the proximity of cardiac sympathetic nerve innervation
Ischemiaâ cardiomyocyte resting membrane potential andâ action potential duration
Voltage gradient between normal and subendocardial ischemic zones creates injury currents, shifting the ST- vector on ECG
ECG: ST depression
and/or T wave inversion
Cardiac sensory nerve fibres mix with somatic sensory nerve
fibres and enter the spinal cord via the T1-T4 nerve roots
Brain perceives increased cardiac sensory nerve signaling as nerve pain coming from the skin of T1-T4 dermatomes (“Referred Pain”)
Myocardial ischemia causes hypoxic stress on cardiomyocytesàâaerobic (requiring oxygen) metabolism,áanaerobic (not requiring oxygen) metabolism
áanerobic respirationálactic acid production,á[H+], andâcellular pH which impairs cardiomyocyte function
Cardiomyocyte dysfunction impairs myocardial relaxation in diastole and/orâ left ventricular contractility in systole
âleft ventricular cardiac output àbackup of blood in the left ventricle, atrium, and pulmonary vasculature
ápulmonary capillary pressures pushes fluid out of the capillaries into the alveoli in the lungs
Fluid filled alveoliâgas exchange andâ oxygenation, triggering harder and faster breathing in order to compensate
Dyspnea
                                 Activation of sweat glands via acetylcholine release
Hormones bind to cardiac β1 receptors
Tachycardia
(áheart rate)
Epinephrine/ Norepinephrine hormone release from the adrenal medulla
Hormones bind to arterial smooth muscle α1 receptors ávascular tone (vasoconstriction)
Hypertension
The Vagus nerve sits in close physical proximity to the inferior wall of the heart àinferior wall ischemia triggers involuntary Vagus nerve activation
Since the Vagus nerve coordinates parasympathetic activity,áVagus nerve activity leads to a variety of parasympathetic nervous system responses:
Retrosternal discomfort: May present as pain, heaviness, tightness, aching, pressure, burning or squeezing
Pain radiation to T1-T4 dermatomes:
Left shoulder and arm, lower jaw, neck, abdomen, upper back
           Syncope
(fainting)
Bradycardia
Nausea Hypotension
        (âheart rate)
(âblood pressure)
  (áblood pressure)
(shortness of breath)
 Legend:
 Pathophysiology
 Mechanism
 Sign/Symptom/Lab Findings
  Complications
Published Oct 18, 2015, updated Aug 29, 2021 on www.thecalgaryguide.com

Angina Pektoris Angina Stabil: Patogenesis dan Temuan Klinis

Angina Pektoris/Angina Stabil: Patogenesis dan Temuan Klinis

Stable Angina

Angina Pectoris/Stable Angina: Pathogenesis and clinical findings
Authors: Ryan Iwasiw Alexander Arnold Julia Gospodinov Reviewers: Mandy Ang Sarah Weeks* Frank Spence* Shahab Marzoughi * MD at time of publication
 Atherosclerosis
(Fatty plaque accumulates inside the intimal walls of arteries)
↓ Blood vessel lumen diameter
↓ Volume of blood is supplied to the heart
Predictable period of physical activity or emotional stress
    ↑ Heart rate
↓ Time for coronary arteries to fill heart with blood (diastole)
↑ Heart contractility
↑ Oxygen demand of heart muscle tissue (myocardium)
         ↓ Myocardial blood supply
Imbalance between blood supply & oxygen demand causes myocardial ischemia
Angina Pectoris/Stable Angina
      Myocardial ischemia causes cardiac muscle cells (cardiomyocytes) to switch from oxygen-dependent (aerobic) to oxygen-absent (anaerobic) metabolism
Anaerobic metabolism produces metabolites that stimulate cardiac spinal afferent nerves
Myocardial visceral afferent & somatic sensory nerve fibers mix & enter the spinal cord via T1-T4 nerve roots
Brain interprets ↑ nerve signaling as nerve pain coming from the skin of T1-T4 dermatomes (referred pain)
↑ lactic acid production & ↓ cellular pH impairs cardiomyocytes’ function
Damaged cardiomyocytes impair myocardial relaxation & cause ↓ left ventricular contractility & cardiac output
Blood backs up into left ventricle, atrium, & pulmonary vasculature
↑ Pulmonary capillary pressures pushes fluid out & into the lung’s alveoli
↓ Gas exchange & oxygenation
↑ Respiratory rate & Dyspnea (shortness of breath)
Blood flow begins at the epicardium (outer heart layer) & ends at endocardium (inner layer)
Subendocardium (innermost heart layer) receives the least blood flow causing non-transmural (partial thickness) heart wall ischemia
Anterior/septal & lateral wall ischemia triggers ↑ sympathetic nervous system (SNS) activity given the proximity of cardiac SNS innervation
Inferior wall ischemia triggers involuntary ↑ in Vagus nerve activity given the nerve’s proximity
          Bradycardia (↓ heart rate)
Nausea
      Adrenal medulla releases Norepinephrine hormone
Activation of sweat glands via SNS acetylcholine neurotransmitter release
Hypotension (↓ blood pressure)
        Pain radiation to left arm, jaw, abdomen & upper back
Chest pain, pressure, or discomfort
Unstable Angina (unpredictable & worsening chest pain)
See relevant Calgary Guide slide on Unstable Angina
Binds arterial smooth muscle α1 receptors
↑ Coronary arteries’ vascular tone (vasoconstriction)
Hypertension (↑ blood pressure)
Activates β1 receptors in the heart
Tachycardia (↑ heart rate)
Diaphoresis (↑ sweating)
       Legend:
 Pathophysiology
 Mechanism
 Sign/Symptom/Lab Finding
 Complications
 Published Aug 8, 2013; updated Feb 5, 2024 on www.thecalgaryguide.com

不稳定型心绞痛

不稳定型心绞痛:发病机制及临床表现

Angina Stabile

Angina Pectoris/Angina Stabile: Patogenesi e riscontri clinici

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