May, 2011 | Master Of Medicine

Monthly Archives: May 2011

Anti arrythmic drugs classification

Anti arrhythmic drugs are classified into four main classes.

Class I – Sodium channel blockers(act on Phase 0)

Class II – Beta blockers(act on phase 4)

Class III- Potassium channel blockers(act on phase 3)

Class IV – Calcium channel blockers(act on phase 2)

Class I- Na+ channel blockers

Class IA – Quinidine, Procainamide, Disopyramide

Class IB -Lidocaine,Phenytoin,Mexiletine,Tocainide

Class IC -Flecainide,Encainide,Propafenone,Morocizine

Class II -Beta blockers

Propranlol,Acebutolol,Esmolol

Class III- K+ Blockers

Amioderone,Bretylium,Ibutilide,Dofetilide,Sotalol

Class IV – Ca2+ blockers

Verapamil,Diltiazem

Heart murmurs and their physiologic responses to stress

Heart murmurs vary in quality and duration with specific physiological influences.Knowing these changes can help us differentiate between specific murmurs.

Respiration

Inspiration

Right sided heart murmurs become loud with inspiration

  • Systolic sounds – TR/PS
  • Diastolic sounds – TS/PR
  • Right sided s3 and s4 also become louder

Expiration

  • Left sided heart murmurs become loud with expiration.
  • Pulmonic ejection sound also becomes louder.

Valsalva manuever

  • Most murmurs decrease in length and intensity with valsalva.
  • Two exceptions are HCM and MVP.

 

Postional changes

Standing

  • Most murmurs decrease in intensity
  • Exceptions are HCM and MVP

Squatting

  • Most murmurs become more intense with squatting
  • Exceptions are HCM and MVP which become softer.

Passive legraising

  • All murmurs except HCM and MVP increase in intensity

Exercise

  • Murmurs due to blood flow across normal or stenotic valves(PS and MS) become louder with isotonic and Isometric (handgrip)exercise.
  • MR,VSD and AR also increase with handgrip.
  • Leftsided S3 and S4 gets accentuated
  • HCM decrease with near maximum handgrip.

 

Adenoid cystic carcinoma

  • Adenoid cystic carcinoma is also called cylindroma .
  • Constitute 10% of all salivary neoplasm
  • 65% of minor salivary gland tumours are malignant, of them 40% are adenoid cystic carcinomas.
  • Most common malignant tumour of minor salivary glands
  • Seen equally in males and females in 6th decade of life
  • Characterized by perineural spread and may lead to facial N palsy
  • Distant metastasis to lungs via hematogenous route.

Three histological types:

  1. Tubular
  2. Cribriform
  3. Solid

 

Brilliantly transilluminant swellings

  • Vaginal hydrocele
  • Epididymal cyst
  • Cystic hygroma
  • Ranula
  • Meningocele

Drug induced lupus, drugs causing it.

Features of drug induced lupus are:

  • ANA positive,Anti Histone antibody positive.
  • Caucasians are more affected.
  • Less female predilection compared to SLE.
  • Rarely involves kidney or brain.
  • Rarely associated with anti ds DNA positivity.
  • ANA will be positive even before the appearance of symptoms.

Drugs causing drug induced lupus.

  • Anti arrhythmic drugs¬† – Procainamide,disopyramide,propafenone.
  • Anti hypertensives — Hydralazine
  • ACE inhibitors and Beta blockers
  • Anti thyroid – Propylthiouracil
  • Antipsychotics – Chlorpromazine, Lithium
  • Anticonvulsants – Carbamazepine,Phenytoin
  • Antibiotics – Isoniazid, Minocycline, Macrodantin
  • Antirheumatic – Sulfasalazine
  • Diuretic – Hydrochlorothiazide
  • Anti hyperlipidemic – Lovastatin, Simvastatin
  • Interferons and TNF alfa inhibitors

 

Tetrad of congenital Toxoplasmosis

Congenital toxoplasmosis is characterized by the classical tetrad described below

  1. Hydrocephalus/Microcephaly
  2. Chorioretinitis
  3. Convulsions/seizures
  4. Cerebral calcification

Bacterial diarrhea: Invasive vs Non Invasive diarrhea.

Bacterial diarrhea’s can be classified into invasive and non invasive, this classification has an important role in determining treatment modalities.

Non Invasive Diarrhea

  • Caused by release of toxins from bacteria resulting in disruption of secretory process.
  • Characterized by watery diarrhea.
  • Blood and fecal leucocytes are characteristically absent.

Bacteria associated are:

  1. Staphylococcus aureus.
  2. Bacillus cereus
  3. Clostridium perfingens
  4. Enterotoxigenic E.Coli(ETEC)
  5. Vibrio cholerae

Invasive diarrhea.

Caused by direct damage to gastrointestinal tissue due to direct invasion by bacteria.

Diarrhea is characterized  by:

  • Fever
  • Dysentry(Blood in stools)
  • Fecal leucocytes

Bacteria associated are:

  1. Shigella
  2. Salmonella
  3. Yersenia enterocolitica.
  4. Enteroinvasive Ecoli(EIEC)
  5. Aeromonas
  6. Plesiomonas
  7. Listeria monocytogenes

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