Cardiac Pathology full😍

Myocardial Infarction (MI)

Autopsy Findings in Myocardial Infarction

• Findings depend on duration of ischemia.

Complications

• Anterior transmural myocardial infarction → aneurysm
• It occurs as a result of the loss of contractile function +
• thinning of the infarcted myocardial wall.

Carditis (Inflammation of the Heart)

 

Pericarditis

• Serofibrinous Pericarditis:
• Associated with: Rheumatic Heart Disease (RHD).
• Description:
• Abundant fluid (watery) +
• fibrous threads between parietal and visceral pericardium.
• Known as: "Bread and Butter Pericarditis".

Myocarditis

1. Causes:
• Viral: Coxsackie virus, Herpes virus.
• Parasitic: Trichinella spiralis (well-known cause).

Endocarditis

• General feature: Vegetations (verrucae) common to all types.

• Four Types:

• Immunological phenomenon
• Oslers ( Oh... painful 😖 hand, Made into Pulp)
• Painful, red nodules on pulp of fingers and toes.
• Immune Complex mediated.

• rOths spot
• Seen in fundus with pale center (Fibrin plug).
• Caused by retinal endothelial vasculitis
• GlomerulOnephritis syndorme

Roth spot seen in

• Infective endocarditis

• Acute leukemia

Cardiomyopathy

 

Dilated Cardiomyopathy (DCM)

• Dilation: All four chambers of the heart.

• Causes:
• Most Common: Idiopathic.
• Known Cause : 
• Alcoholism
• Doxorubicin
• Trastuzumab
• Peripartum myopathy
• Most Common Genetic Cause: 
• Titan gene mutation (largest protein).
• Hemochromatosis → DCM > RCM

• Microscopic Finding: 
• Ninja star appearance of cardiac fiber nucleus
• linked to alcoholism/Titan mutation
• Myocyte vacuolization

• Mnemonic:
1. DCM → DC/Marvel → Drunk Titan (Titin) Ninja (Ninja star) → Got Fat (dilated) Excess alcohol drinking → He was tight (Trastuzumab), has a dog called ruby (Doxorubicin)

Takotsubo Cardiomyopathy / Broken Heart Syndrome:

• Dilation: Only left ventricle (resembles octopus pot - "Takotsubo").

• Cause: Extreme emotional stress → increased catecholamines.

• "Broken Heart Syndrome": refers to pathogenesis (emotional stress).

• Mnemonic: Takotsubo → Takashis castle → Got heart broke when it ended

Hypertrophic Cardiomyopathy (HCM)

• Mnemonic: Myren (Myosin) Dominant (AD) Hitler (Helter skelter) → Ordered to kill Awesome (HOCM) Athlete (called SAM → Systolic Ant Motion of MV) → while eating banana (Banana shaped heart) → in Camp (Mevampton)

• Mutation: Myosin Heavy Chain (MHC) mutation.
• New drug Rx → Mevacampton

• Inheritance: Autosomal Dominant.

• Hypertrophy: More in
• left ventricle 
• interventricular septum.

• Clinical Presentation: Often sudden death in a young athlete.

• Gross Appearance: 
• Banana-shaped heart with a slit-like chamber.

• Microscopic Finding:
• Cardiac muscle fibers in random directions
• Myocyte disarray → ("Helter Skelter appearance").

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVCM)

• Involvement: Right ventricle.

• Mutation: Desmosomes (specifically, Plakoglobin gene defect).

• Gross/Microscopic:
• Right ventricle wall very thin
• appears yellow due to fatty infiltration.

• ECG
• Epsilon wave

• Associated Syndrome: Naxos Syndrome.
• Components: ARVCM + woolly hair + palmoplantar keratoderma.

• Mnemonic: Rv (ARV) il oru Fat (fat deposition) Nexalate (NAxos) ne kandu → He had plaques (plakoglobin) on hair (woolly hair) and hands (keratosis) → He was Desp (Desmosomes)

Restrictive Cardiomyopathy (RCM)

• Dysfunction: Diastolic dysfunction (heart cannot relax).

• Most Common Cause: 
• Amyloidosis (amyloid protein in heart).

• Other causes:
• Hemochromatosis (DCM > RCM)
• Sarcoidosis
• Fibrosis
• Loefflers Sx

Hemochromatosis

• Dilated cardiomyopathy > RCM OR BOTH

Cardiac Hypertrophy

• Boxcar nuclei

• Secondary to hypertension or stenosis
• eg mitral stenosis

• NOT HOCM

Bacillus anthracis

• Boxcar appearance aka bamboo stick appearance

• Gram staining

Lymphocytic myocarditis

• Fever, fatigue, and left ventricular dysfunction

• Endomyocardial biopsy
• Lymphocytic infiltration

Miscellaneous Cardiac Topics

Candy (Gundy) and Nutmeg

ㅤ	Heart Failure	Site	Notes
Nutmeg Liver	Right	Liver	Congested hepatic veins with centrilobular hemorrhagic necrosis of hepatocytes (dark color) Periphery → fatty changes (light color)
Gamma Gandi Bodies	Right	Spleen	Venous congestion
Heart Failure Cells/ Hemosiderin Laden macrophage	Left	lungs	Macrophages that have engulfed hemosiderin  (iron-containing pigment).

BRUGADA SYNDROME

• Brutal (Brugada) scene (SCN5A)
• guy like me (pseudo RBB) → drinking soda (Na channelopathy)
• sudden seizure and death ()

• Loss-of-function SCN5A

• Pseudo-RBBB

• AD

• Etiology:
• Channelopathy: Na channel.
• S2 elevation: No channel.

• Risk:
• Can lead to sudden cardiac death.

• Clinical Features (C/F:):
• Syncope.
• Seizure mimic.

• ECG findings:
• V1, V2: Coved S2 elevation.
• V1 - V₆: STE + incomplete RBBB.

• Treatment (Rx:):
• Intra cardiac Defibrillator.

Intra Cardiac Defibrillator

Cardiac Tumors

Most Common Cardiac Malignancy

• Metastasis (mets) (cancer spread from other body parts to heart).

Primary Cardiac Tumors (Within the Heart)

Details of Specific Primary Tumors

Mnemonic:

• Rhabdomyoma → Rat (Rhabdomyoma) and Spider (spider cells) in a Pasta (PAS positive) tube (Tuberous sclerosis)

• Myxoma → Mixed in Los Angles (Left atrium) → Leopard (Lepidic) Kaarnnu (Carney) Nashipich (gNAS)

• Most Common Cardiac Valve Tumor:
• Papillary Fibroelastoma (PFE).
• Appearance: Many papillary projections → "sea anemone-like appearance".

ACUTE RHEUMATIC FEVER

• Roomatic fever
• Vijayan → Jai Vigyan
• Marginal ds (Erythema marginatum)
• Carry and Oomb in Middle of room → Carey coomb murmur
• Give mouth like a fish in her button hole (Fish mouth/Button hole stenosis)
• Show ass everywhere (Aschoff bodies → All layers → max in myocardium), Apply some butter (bread and butter → fibrinous pericarditis)
• Do Per Rectal (Prolonged PR)
• Buy benz (Benzathine Penicillin) & Get 12 lakh every 3 weeks () (for adults)

Etiology and Pathogenesis

• Etiology:
• Post streptococcal disorder
• Group A β hemolytic streptococci (Strains: 1, 3, 5, 6, 18)

• Age: School-going children (5-15 years).

• Incidence: m = F.

Pathogenesis:

• Pharyngitis
• 10 days to few weeks

• Type II hypersensitivity reaction (antibody mediated).
• Streptococcal M-protein cross reacts with 
• glycoprotein in heart and joints
• molecular mimicry

Affected Valves

• Most common valve affected: 
• mitral valve.

• Least common valve affected: 
• Pulmonary valve.

• Mitral valve (F > m) > Aortic valve (m > F).

Presentations

• Acute RHD: 
• mitral regurgitation.

• Chronic RHD: 
• mitral stenosis.

LAE/Mitral stenosis:

• Straightening of left heart border (Image 1).

• Splaying of carinal angle.

• Double density sign/ double right heart border sign (Image 2).

• Walking man sign:
• lateral chest x-ray (Image 3).
• Left atrium cause elevation of left bronchus

• Third Mogul sign (Image 4):
• Prominent third Mogul
• because of left atrium.

• Dysphagia
• Left atrium → Esophageal compression (Image 5)
• Trans esophageal echocardiography (TEE) is done.

Chamber Enlargement Signs

• RVH: Apex up.

• LVH: Apex down and out.

Revised Jones Criteria

Major Criteria (J.O.N.E.S)

1. Joint Arthritis: 
• Monoarthritis / Polyarthritis / Polyarthralgia
• Migratory polyarthritis:
• Involving large joints.
• Non-erosive.
• Excellent response to aspirin.
• Complete recovery (No residual joint damage)
• DONT include MONOARTHRALGIA

2. Pancarditis:
• Clinical
• Subclinical (ECHO Findings+)

3. Subcutaneous nodules.
• Painless.

4. Erythema marginatum.
• Most common & earliest manifestation.
• Raised rash, sparing the face.
• Transient

5. Sydenham's chorea.
• DOC: Haloperidol

Minor Criteria

1. Clinical:
• Fever.
• Monoarthralgia

2. Laboratory:
• ↑ ESR.
• ↑ CRP.

3. ECG
• ↑ PR interval.

• CAFE Pal

Essential Criteria

1. ↑ ASO titre.

2. Throat swab positive for streptococci:
• Risk of false positive/negative → not preferred.

3. History of preceding sore throat (< 50%).

Diagnosis

• All cases require Essential criteria.

• First Episode:
• 2 major criteria OR
• 1 major + 2 minor criteria

• Recurrence:
• 2 major criteria OR
• 1 major + 2 minor criteria OR
• 3 minor criteria

• Mnemonic: Jones → JO → start from 2 major criteria

Pancarditis

• Early finding (within 2 weeks).

• Most serious: 
• Permanent damage of valves can occur.

• Most common feature of ARF 

Pericardium:

Fibrinous pericarditis

• Pericarditis: chest pain + frictional rub.

• Deposition of fibrinous exudate between the layers of pericardium.

• Appearance: Bread and butter appearance.

Myocardium: 

• Aschoff bodies.
• Pathognomonic of RHD.
• Seen in all layers.
• Maximum in myocardium.
• Components:
1. Anitschkow
• AKA caterpillar cells.
• Macrophages with slender wavy ribbon-like nuclei.
2. Fibrinoid necrosis.
3. Inflammatory cells.

Types of valvulitis:

Mitral valvulitis:

• Carey coombs murmur (delayed diastolic murmur).

• CC murmur → DD murmur

Mitral regurgitation:

• In acute RHD 
• Soft S₁
• Pan systolic murmur.

• Hemodynamic overload → LVF (morbidity/mortality in ARF).

Mitral Stenosis

• In chronic RHD 
• fibrosis & calcifications of MV.
• Loud S₁

• Fish mouth/Button hole stenosis 

Subendocardial Jets / McCallum Plaques

• Thickening of left atrial wall due to mitral regurgitation.

Mitral Valve Thickening / Commissural Fusion

• Shortening & thickening of chorda tendinae.

Vegetations

• Size: 1-4 mm.

• Appearance: Small, warty, verrucous, sterile lesions.

• Location: Along the lines of closure of valve leaflets.

Treatment & Prophylaxis

Treatment:

• Bed rest for 2 weeks.

Penicillin:

1. Benzathine Penicillin G:
• > 30 kg: 
• 1.2 million/ 12 lakh IU every 3 weeks.
• < 30 kg: 
• 6 lakh IU every 2 weeks.

2. Oral Penicillin V: 
• 250 mg BD.

3. If allergic to Penicillin:
• Erythromycin 250 mg BD.

Anti-inflammatory Medications

• For 12 weeks
1. Steroids:
• Preferred (especially in cardiac problems).
• Oral Prednisolone: (12 weeks - 3/9)
• 2 mg/kg/day (max 60 mg/day) x 3 weeks 
• → Taper over 9 weeks.
2. Aspirin: (12 weeks - 10/2)
• 90-120 mg/kg/day in 4 divided doses x 10 weeks 
• → Taper over next 2 weeks.

Duration of Prophylaxis

Scenario	Prophylaxis Duration
No carditis	For next 5 years or till age 18, whichever is longer.
Carditis (without Residual Heart Disease)	For next 10 years or till age 25, whichever is longer.
Established Residual Heart Disease/ underwent surgery	Till age 40  (Ideal: Life long).

Infective Endocarditis - Introduction

• Definition:
• Infection of valvular endocardium and mural endocardium.

• IE occurs on a damaged valve (native or prosthetic) or an intracardiac device.

• Predisposing Factors/Damage Types:
• Congenital: 
• Mitral valve prolapse (MVP) is most common.
• Rare: ASD, MS, MVP without MR.
• Rheumatic:
• Often left-sided. 
• Mitral valve >> Aortic valve.
• Degenerative:
• Aortic stenosis (in elderly).
• IV drug abuse:
• Often right-sided
• Tricuspid valve affected.

• Common Locations:
• Left-sided IE (75%):
• Mitral Valve commonly involved.
• Right-sided IE (10%):
• In IV drug abusers (Tricuspid valve affected).
• Mixed: 15%.

• Other General Notes:
• MC congenital heart lesion: 
• VSD.
• IV catheters in CKD patients can lead to IE.
• Mitral valve involvement: 
• MVP +MR

Pathogenesis

Acute vs. Subacute IE

Features (primarily in Subacute IE)

• New onset murmur or worsening of murmur.

• Arterial embolization:
• Stroke, mesenteric ischemia, acute coronary syndrome.

• Clubbing and Splenomegaly.

Complications

• Heart Failure:
• New onset
• Due to valvular insufficiency.

• Embolization:
• ACS, Stroke.

• Perivalvular Abscess:
• Conduction Abnormalities or 
• persistent fever with a lesion near the aortic valve.

• Right-sided IE Specific Complications
• Common in IV drug abusers.
• Fever + Septic Pulmonary Emboli.
• Right heart failure, Pulmonary abscess
• Mycotic aneurysm of pulmonary artery.

Diagnosis (Duke's Criteria)

• 2 major OR 

• 1 major plus 3 minor OR 

• 5 minor criteria.

Major Criteria

1. Blood Culture:

• 3 sets from 3 sites.

• Each set 20 ml (1 aerobic / 1 anaerobic) over 30 min apart
• Out of which → 1 central sample

• Repeat cultures every 12 to 24 hours.

• Positive Culture
1. Typical Organisms:
• Positive in ≥2 site enough.
2. Atypical Organisms:
• Persistently positive (even after 18-24 hours).
3. Coxiella Burnetii:
• Single Sample positive OR 
• PCR positive.
4. IFA for Bartonella for IgG and IgM

2. Involvement of heart valves

1. Echocardiogram Findings:
• TEE >> TTE.
1. Vegetations.
2. Abscess.
3. New onset AR or MR.
4. New partial dehiscence of the prosthetic valve.
• Indications for TEE:
• Prosthetic valves.
• Cardiac implantable electrical device.
• Myocardial abscess.
• Valvular perforation.
• Vegetations <3mm.
• Presence of Intracardiac Fistula.

2. Cardiac CT

3. FDG PET

4. Direct visualisation during heart surgery

Minor Criteria

1. Predisposing Heart disease.

2. Fever ≥ 38°C.

3. Vascular phenomena:
• Major emboli
• Splenomegaly
• Clubbing
• Micro-embolization
• Petechiae:
• Most common.
• Found on palpebral conjunctiva, buccal & palatal mucosa, extremities.
• Splinter/Subungual Haemorrhages:
• Dark red, linear or flame-shaped streaks.
• Located in proximal nail bed.
• Janeway lesion
• Non-tender, small, erythematous macular or nodular lesions
• soles or palms.

4. Blood culture not meeting major criteria.

5. Immunological complications
• Immunological phenomenon
• Oslers ( Oh... painful 😖 hand, Made into Pulp)
• Painful, red nodules on pulp of fingers and toes.
• Immune Complex mediated.

• rOths spot
• Seen in fundus with pale center (Fibrin plug).
• Caused by retinal endothelial vasculitis
• GlomerulOnephritis syndorme

Roth spot seen in
• Infective endocarditis
• Acute leukemia

Other Laboratory Tests

• Anemia.

• WBC count increased in acute IE.

• Thrombocytopenia is rare.

• ESR elevated in all patients.

• Rheumatoid factor ↑↑ in 50% (Immunological).

• MPGN

Treatment

Antibiotic Regimens

Surgery Indications

• Native Valve IE:
• Acute AR or MR with evidence of increased filling pressure.
• Fungal Endocarditis.
• Acute valve stenosis or regurgitation with Heart Failure.
• Complicated by heart block, annular or aortic abscess.

• Prosthetic Valve IE:
• Heart failure.
• Dehiscence.
• Increasing obstruction/worsening regurgitation.

Secondary Prophylaxis (To prevent further episodes/carditis):

• PROPHYLAXIS NOT NEEDED IN ASD

• Dental procedures.

• Invasive procedures: 
• Tonsillectomy, Adenoidectomy.

Prophylaxis Regimen

• Sensitive to Penicillin:
• Amoxicillin 2g orally 30-60 min before surgery.

• Unable to take oral meds:
• Ampicillin 2g IV or IM. OR
• Ceftriaxone 1g IV or IM.

• Allergic to Penicillin:
• Oral cephalexin 2g.
• Oral clindamycin 600 mg.
• Oral azithromycin 500mg.

• Allergic to Penicillin + Unable to take oral meds:
• Clindamycin 600mg IV or IM.