Cardiomyopathies; Investigation of microcirculations, Raynaud-syndrome

Question 1

What are Cardiomyopathies?

Answer 1

They are cardiac diseases due to intrinsic myocardial dysfunction. Can be Primary [mostly idiopathic] or Secondary [to an identifiable cardiac injury]

Question 2

Types of Cardiomyopathies

Answer 2

• Dilated Cardiomyopathies
• Hypertrophic Obstructive Cardiomyopathies
• Restrictive Cardiomyopathies
• Arrhythmogenic Right Ventricular Cardiomyopathies

Question 3

Dilated Cardiomyopathy [Etiology, Pathophysio, Clinical Features, Dx, Treatments]

Answer 3

Etiology:
- Idiopathic
- Genetic [TTN gene mutation]
- Viral infection causing myocarditis [Coxsackie B]
- Systemic disorders [Sarcoidosis, Hemachromatosis]
- Toxic substances [Alcohol abuse, Cocaine, Chemo drugs]

Pathophysio:
- Eccentric hypertrophy of ventricles
- Decreased contractiliy from cardiac remodelling
- Decreased EF
- Heart Failure

Clinical Features:
- Slowly progressive HF
- MR
- Arrhythmias
- Exertional dyspnea
- Edema

Dx:
- ECG
- CXR [hypertrophy and enlarged heart silhouettes]
- TTE [shows dilated heart wall diameters, volumes, wall movements, EF]

Treatment:
- ACE inhibitors
- Beta Blockers
- Diuretics
- Aldoesterone Receptor Blockers
- Digoxin
- Heart transplant in severe dilated cases

Question 4

Hypertrophic Obstructive Cardiomyopathies [Etiology, Pathophysio, Clinical Features, Dx, Treatments]

Answer 4

Etiology:
- Myosin binding protein C, Beta-myosin heavy chain AD missense mutations
- HTN, AS, Amyloidosis

Pathophysio:
- Excessive concentric hypertrophy [including intraventricular septum] causes Diastolic dysfunction [Filling defect]
- Decreased Myocardial and Peripheral perfusion
- Left Ventricular Outflow Track obstruction and Mitral Regurgitation [due to systolic anterior movement of mitral valve]

Clinical Features:
- Dyspnea
- Syncope
- Angina
- Ventricular Arrhythmias [needs immediate therapy]

Dx:
- TTE [shows septum hypertrophy and wall thickness, dynamic obstruction of blood flow]
- ECG [LV hypertrophy signs and ST segment changes]
- CXR [Heart enlargements]
- Auscultations will show valve based murmurs

Treatments:
- Beta Blockers
- Non-dihydropyridine CCBs [Verapamil]
- In advanced disease, Septal myectomy, Catheter therapy [ablation]

Question 5

Restrictive Cardiomyopathies [Etiology, Pathophysio, Clinical Features, Dx, Treatments]

Answer 5

Less compliant heart walls but without changes in heart size ['’stiffness’’]

Etiology:
- Amyloidosis
- Endocardial Fibroelastosis
- Loffler Syndrome [eosinophil infiltrations causing fibrosis]

Pathophysiology:
- Deposition or Fibrosis in heart walls
- Heat walls become less compliant and lose contractility
- Diastolic Heart Failure

Clinical Features:
- Signs of Left and Right Heart Failure

Dx:
- TTE [EF normal but Diastolic filling reduced]

Treatments:
- Diuretics
- Beta Blockers
- Heart Transplantation in severe restrictive cardiomyopathies

Question 6

Arrhythmogenic right ventricular cardiomyopathy [Etiology, Pathophysio, Clinical Features, Dx, Treatments]

Answer 6

Etiology:
- Desmosome proteins gene mutations [form tight junctions in myocardium]

Pathophysio:
- Primarily affects RV
- Fibrofatty replacement of myocardium
- Myocardial thinning
- Ventricular dilation

Hallmark is Arrhythmias however symptoms are broad

Dx:
- TTE and TEE
- ECG
- CXR

Treatments:
- Amiodarone
- Sotalol
- Beta Blockers
- ICDs
- Catheter ablation in selected cases

Question 7

What parameters can influence microcirculation?

Answer 7

• Temperature
• Systolic Blood pressure
• Physical activity
• General status [stress, food, medications, smoking]

Question 8

What investigations are used for microcirculations?

Answer 8

• Laser Doppler: Measures Total local microcirculatory blood perfusion
• Laser Speckle Contrast Analysis: Forms speckle patterns to visualize tissue blood perfusion instantaneously
• Transcutaneous Oximetry: Reflects amount of O2 that has diffused from capillaries through the epidermis. It is used to determine peripheral vascular oxygenation
• Nailfold Capillary microscopy: Microscopy used to visualize capillaries under nail folds and nail beds, in order to diagnose certain rheumatological and other disorders of microvasculature

Question 9

What is Raynauds phenomenon? How is it classified?

Answer 9

Raynauds phenomenon is the exhaggerated vasoconstriction [often vasospastic] of distal arteries and arterioles, most commonly in fingers and toes. This cuts off blood supply to the tissue either briefly [most common outcome] or long enough to cause ulcers and gangrene [less common outcome]

It is broadly classified into Primary [previously, Raynauds Disease] and Secondary [previously, Raynauds Syndrome] Raynauds phenomenon

Primary RP is idiopathic, with 50% increased incidence with first-degree family history. Occurs around < 30 years of age

Vasospastic attacks highly associated with Cold or Emotional stress as stimulators

Question 10

Raynauds Syndrome [Etiology, Clinical Features, Dx, Treatments]

Answer 10

Etiology: Vasospasms precipitated by
- Connective Tissue Diseases [Scleroderma or CREST syndrome, SLE, Sjogrens, MCTD]
- Vasculitidies [Beurgers Disease]
- Hyperviscocity [Cryoglobulinemia, Waldestromes macroglobulinemia, Polycythemia]
- Drugs [Beta Blockers, Ergotamine, Oral contraceptives]
- Smoking
- Occupational exposure [Handling vibrating tools, typing]
- PAD
- Frostbite
- Carpal Tunner syndrome, Intervertebral Disc Disease

Clinical Features:
- Classically in fingers and toes, but also affects ears, nose, areolar tissue, tongue
- Typical Triphasic presentation: Ischemic White [blood cut off]; Hypoxic Blue [no fresh O2 and degen of residual blood]; Hyperemic Red [not always present, after restoration]
- Livedo reticularis may occur
- Critical ischemia can bring severe pain and ulcerations/necrosis
- Associated symptoms of underlying disease [telengectasia, sclerodactyly, skin fibrosis, etc]
- PAD features are typically absent, unless an underlying cause

Dx:
- Clinical diagnosis
- Lab studies: CBC, ANA and Extanuclear Antibody panel, ESR or CRP
- Nailfold Capillary microscopy [evaluate architecture, capillary density, size, hemorrhages]
- Cervial spine and Upper Thoracic imaging [to evaluate for Thoracic Outlet Syndrome]

Treatments: Overall aim is to treat underlying cause first
- Trigger avoidance [cold and stress management can help a lot]
- Calcium Channel Blocker monotherapy
- IV prostanoid therapy for severe ischemic cases +/- Botulinum Toxin
- Endothelin-1 receptor antagonist [in scleroderma patients]
- Botulinum toxin injections
- Selected Digital sympathectomy [cuts off sympathetic innervation to digit vessel]