Compensatory mechanism

Renin-Angiotensin-Aldosterone-System (RAAS)
Neurohormonal response – RAAS
Endothelin release (contractility)
Cytokine release (Hypertrophy)
Inadequate stroke volume and CO – (Epi and NoreEpi)
Ventricular remodeling
- Continuous activation of neuro-hormonal responses (RAAS and SNS)
- Hypertrophy of ventricular myocytes
- Ventricles larger but less effective in pumping
- Can cause life-threatening dysrhythmias and sudden cardiac death
Dilation
- Enlargement of chambers of heart that occurs when pressure in left ventricle is elevated
- Initially effective
- Eventually this mechanism becomes inadequate and CO decreases
Hypertrophy
- Increase in muscle mass and cardiac wall thickness
- Initially effective
- Over time leads to poor contractility, increased O₂ needs, poor coronary artery circulation, and risk for ventricular dysrhythmias

Counterregulatory mechanism

Natriuretic peptides
- Atrial natriuretic peptide (ANP),
  b-type natriuretic peptide (BNP)
- Released in response to increased blood volume in heart
- Causes diuresis, vasodilation, and lowered BP
- Counteracts effects of SNS and RAAS
Nitric oxide (NO) and prostaglandin
- Released from vascular endothelium in response to compensatory mechanisms
- NO and prostaglandin relaxes arterial smooth muscle, resulting in vasodilation and decreased afterload

Shoulder Dislocations Overview

Rachel Abrams; Halleh Akbarnia. Author Information and Affiliations Last Update: August 8, 2023. Go to: Continuing Education Activity Shoulder dislocations represent 50 percent of all

About High Blood Pressure

For Everyone JANUARY 28, 2025 About High Blood Pressure KEY POINTS High blood pressure (hypertension) is consistently at or above 130/80 mm Hg. High blood

Childhood asthma and exercise

Daniel Hughes ✉ Author information Article notes Copyright and License information PMCID: PMC4235445 PMID: 25414580 Children with asthma, similar to most children, enjoy being physically active,