AJIRA ZETU BLOG

  Infective Endocarditis (IE)   Definition :   Infection of the endothelium of the heart, usually but not limited to the valves. Can be divided according to either subacute onset (often due to Strep viridians ) or acute onset (less common, often due to Staph aureus ).   Pathophysiology: Infection of the valves with bacteria (or rarely fungi) cases injury to the valve and valvular regurgitation. The bacteria continues to grow on the valve and can form a large mass or vegetation. Parts of this vegetation can embolize to other parts of the body. The immune response to these organisms leads to the production of immune complexes. Essentially, infection of the endothelium causes 1) persistent bacteremia, 2) valvular disfigurement (with vegetations/regurgitation), 3) septic emboli and 4) immune complex phenomenon.   Predisposing conditions: 1.       Abnormal valve* : prior endocarditis, h/o rheumatic heart disease, valvular heart disease...

  Congestive Heart Failure   Definition : Heart failure is the inability of the heart to maintain an output adequate to meet the metabolic demands of the body. It is an increasingly common condition that affects millions of people. It is also associated with high morbidity and mortality. Consider it a syndrome, not a disease.   Pathophysiology:   - Heart failure is manifested as organ hypoperfusion and inadequate tissue oxygen delivery due to low cardiac output and decreased cardiac reserve, as well as pulmonary and systemic vascular congestion. A variety of “compensatory adaptations” occur, including (1) increased left ventricular volume dilatation and hypertrophy, (2) increased systemic vascular resistance (SVR) secondary to enhanced activity of the sympathetic nervous system and elevated levels of catecholamines, (3) activation of the rennin-angiotensin-aldosterone and ADH (anti-diuretic hormone) systems. These mechanisms, with pump failure, play an importa...

    Chest Pain Chest pain is a frequent symptom and may be a manifestation of cardiovascular or noncardiovascular disease.   Full characterization of the pain with regard to quality, quantity, frequency, location, duration, radiation, aggravating or alleviating factors and associated symptoms may help to distinguish among various causes.   Always ask about describing the discomfort in their chest, “squeezing,” “tightening,” “pressing,” “burning.”   All patients presenting to a hospital with severe or persistent chest pain should have a full set of vital signs, an ECG, and a CXR.   Etiologies and signs/symptoms/diagnosis ** The life-threatening causes that must be considered and ruled out in all patients with severe, persistent chest pain.   Cardiac Causes Angina/Myocardial infarction ** Substernal pressure +/- radiation to neck, jaw, Left arm Duration usually > 1 minute and < 12 hours for angina Associated w...

    Arrhythmias (emphasis on Atrial fibrillation)   Definition: Abnormality in cardiac conduction that can manifest as either change in rate or rhythm   Types and etiologies: Bradyarrhythmia: any rhythm that results in a ventricular rate of less than 60 beats per minute. Sinus bradycardia : sinus rate of less than 60 beats/minute. Has normal P wave configuration consistent with origin in sinus node area. Etiology: increased vagal tone, hypothyroidism, ischemia, medication such as digoxin, beta blockers, calcium channel blockers AV Block 1 st degree: conduction delay within AV node, results in prolonged PR interval on ECG of greater than 200 msec. Etiology: medication, CHF, ischemia, electrolyte abnormalities. No therapy needed. 2 nd degree Type I (Wenckebach): progressive PR interval prolongation before a blocked or dropped beat. Etiology: medication, electrolyte abnormalities, ischemia. If s...