Comprehensive Medical Review: Cardiology, Nephrology, Endocrinology, Neurology, Hematology, and Pulmonology

Vocabulary flashcards covering high-yield concepts in cardiology, nephrology, endocrinology, neurology, hematology, and pulmonology from the medical lecture review guide.

Atrial Fibrillation (AF)

The most common sustained chronic arrhythmia, characterized electrocardiographically by chaotic atrial activity replacing P waves with irregular f waves at $350\text{--}600\,\text{bpm}$ and an irregularly irregular ventricular response.

First-Degree Atrioventricular (AV) Block

A supra-Hisian conduction delay characterized on an electrocardiogram by a constant, prolonged PR interval greater than $200\,\text{ms}$ ($> 0.20\,\text{s}$) where every P wave is followed by a QRS complex.

Second-Degree AV Block (Mobitz I and Mobitz II)

An intermittent failure of AV conduction subdivided into Mobitz I (Wenckebach), featuring progressive PR prolongation until a P wave fails to conduct, and Mobitz II, featuring sudden, non-conducted P waves without prior PR lengthening.

Third-Degree (Complete) AV Block

A complete absence of conduction between atria and ventricles showing AV dissociation on the ECG, where regular P waves occur independently of a regular, slower ventricular escape rhythm.

Atrial Flutter

A macroreentrant atrial tachycardia circling the tricuspid annulus at $250\text{--}350\,\text{bpm}$, presenting on ECG with continuous 'saw-tooth' F waves (negative in inferior leads, positive in V1) and typically a 2:1 AV block.

Wolff-Parkinson-White (WPW) Pattern

Ventricular pre-excitation via an accessory pathway between atria and ventricles, recognized on ECG by a short PR interval ($< 120\,\text{ms}$) and an initial slurring of the QRS complex known as a delta wave.

Torsades de Pointes

A form of polymorphic ventricular tachycardia associated with a prolonged QT interval, characterized by QRS complexes whose amplitude and axis twist progressively around the isoelectric baseline.

Brugada Syndrome (Type 1 Pattern)

A sodium channelopathy (most commonly involving SCN5A loss-of-function) presenting on ECG with coved-type ST-segment elevation $\ge 2\,\text{mm}$ followed by an inverted T wave in leads V1 to V3.

Hibernating Myocardium

Viable myocardium with chronic contractile dysfunction resulting from persistent, severe resting hypoperfusion that recovers function following surgical or percutaneous revascularization.

Stunned Myocardium

Viable myocardium that exhibits prolonged post-ischemic contractile dysfunction following an acute episode of ischemia and successful reperfusion, recovering contractility spontaneously over days to weeks.

Resistant Hypertension

Blood pressure that remains uncontrolled ($\ge 140/90\,\text{mmHg}$) despite lifestyle modifications and the concurrent use of optimal doses of at least three antihypertensive agents of different classes, one of which is a diuretic.

Hypertensive Emergency

Severe blood pressure elevation ($\text{SBP} > 180\,\text{mmHg}$ and/or $\text{DBP} > 120\,\text{mmHg}$) associated with acute, progressive target organ damage (e.g., encephalopathy, acute coronary syndrome, aortic dissection, pulmonary edema) requiring immediate intravenous therapy.

Prerenal Acute Kidney Injury

A functional decrease in glomerular filtration caused by renal hypoperfusion with intact tubular cells, typically characterized by urinary $\text{Na}^+ < 20\,\text{mEq/L}$, fractional excretion of sodium ($\text{FENa}$) $< 1\%$, urinary osmolarity $> 500\,\text{mOsm/kg}$, and hyaline casts.

Acute Tubular Necrosis (ATN)

Intrinsic parenchymal acute kidney injury secondary to severe ischemic or toxic tubular cell injury, presenting with urinary $\text{Na}^+ > 40\,\text{mEq/L}$, $\text{FENa} \ge 1\%$, isosthenuric urine ($< 350\,\text{mOsm/kg}$), and muddy brown granular casts.

Secondary Hyperparathyroidism of CKD

An adaptive endocrine disorder in chronic kidney disease driven by hyperphosphatemia, hypocalcemia, and decreased 1,25-dihydroxyvitamin D synthesis, resulting in persistent elevations in parathyroid hormone (PTH) and high-turnover bone disease (osteitis fibrosa cystica).

Euthyroid Sick Syndrome

Abnormalities in serum thyroid function tests in patients with severe non-thyroidal systemic illness, universally characterized by decreased free and total $T_3$, normal or low free $T_4$ and TSH, and elevated reverse $T_3$ ($\text{rT}_3$).

Graves-Basedow Disease

The most common cause of hyperthyroidism in young and middle-aged adults, mediated by autoantibodies against the TSH receptor (TSI) that induce diffuse thyroid hyperplasia, diffuse isotopic hypercapture, and extrathyroidal features such as orbitopathy and pretibial myxedema.

Toxic Adenoma (Plummer Disease)

A solitary autonomous hyperfunctioning thyroid nodule that produces thyrotoxicosis and appears on radioiodine scintigraphy as a single hypercaptating ('hot') nodule with complete suppression of tracer uptake in the remaining thyroid tissue.

Subacute Granulomatous Thyroiditis (de Quervain)

A self-limiting inflammatory thyroid condition, usually viral or post-viral, characterized by an exquisitely tender, painful, enlarged thyroid, elevated erythrocyte sedimentation rate (ESR), an initial thyrotoxic phase with low radioiodine uptake, and giant-cell granulomas on histology.

Papillary Thyroid Carcinoma

The most common differentiated thyroid malignancy ($80\text{--}90\%$ of cases), characterized by slow growth, regional lymphatic spread, psammoma bodies, and an excellent prognosis.

Medullary Thyroid Carcinoma

A neuroendocrine tumor originating from parafollicular C cells of the thyroid producing calcitonin and CEA, associated with germline RET mutations in familial cases (MEN 2A and 2B), and histologically demonstrating sheets of cells with amyloid stroma.

Diabetic Ketoacidosis (DKA)

An acute metabolic complication of diabetes (primarily type 1) characterized by absolute insulin deficiency, marked hyperglycemia (usually $> 200\,\text{mg/dL}$), metabolic acidosis with an elevated anion gap ($\text{pH} \le 7.30$, $\text{HCO}_3^- < 15\,\text{mEq/L}$), and positive serum and urine ketones.

Hyperosmolar Hyperglycemic State (HHS)

A life-threatening acute diabetic emergency (typically in older type 2 diabetics) featuring profound hyperglycemia ($> 600\,\text{mg/dL}$), effective plasma hyperosmolality ($> 320\,\text{mOsm/kg}$), severe dehydration, and altered consciousness without significant ketoacidosis.

Dawn Phenomenon

Early morning hyperglycemia in diabetic patients occurring as a physiological result of nocturnal surges in counterregulatory hormones (growth hormone and cortisol), treated by increasing the evening or basal insulin dose.

Childhood Absence Epilepsy

An idiopathic generalized epilepsy of childhood (onset $4\text{--}10\,\text{years}$) manifesting as brief episodes of sudden loss of awareness without loss of postural tone, precipitated by hyperventilation and characterized by generalized $3\,\text{Hz}$ spike-and-wave discharges on EEG.

Juvenile Myoclonic Epilepsy (JME)

An idiopathic generalized epilepsy presenting in adolescence ($8\text{--}25\,\text{years}$) characterized by bilateral, involuntary myoclonic jerks predominantly in the upper limbs shortly after awakening, frequently triggered by sleep deprivation or alcohol, with polyspike-and-wave EEG activity.

Mesial Temporal Sclerosis

The most common structural cause of drug-resistant focal epilepsy, characterized by hippocampal neuronal loss and gliosis (seen as T2/FLAIR hyperintensity and atrophy on MRI), manifesting with an ascending epigastric aura, automations, and impaired awareness.

Cluster Headache (Horton Headache)

A severe trigeminal autonomic cephalalgia affecting predominantly young-to-middle-aged males, presenting with strictly unilateral, excruciating retro-orbital pain lasting $15\text{--}180\,\text{minutes}$, associated with ipsilateral lacrimation, rhinorrhea, Horner syndrome, and motor restlessness.

Paroxysmal Hemicrania

A trigeminal autonomic cephalalgia occurring more commonly in women, characterized by multiple daily episodes ($5\text{--}30/\text{day}$) of severe unilateral peri-orbital pain lasting $2\text{--}30\,\text{minutes}$, with an absolute, pathognomonic response to indomethacin.

Dacrocytes (Teardrop Cells)

Abnormally shaped erythrocytes resembling teardrops that arise when marrow architecture is infiltrated and distorted by fibrosis, granulomas, or metastatic tumor cells (myelophthisic reaction).

Schistocytes

Fragmented red blood cells produced by mechanical shearing of erythrocyte membranes against fibrin strands in microvascular beds, characteristic of microangiopathic hemolytic anemias (TTP, HUS, DIC).

Anemia of Chronic Disease

A normocytic or microcytic hypoproliferative anemia driven by chronic inflammation and elevated hepatic hepcidin synthesis, characterized by low serum iron, low or normal transferrin/TIBC, and normal or elevated ferritin levels.

Pernicious Anemia

An autoimmune megaloblastic anemia caused by autoimmune destruction of gastric parietal cells, resulting in intrinsic factor deficiency, cobalamin (vitamin $B_{12}$) malabsorption, achlorhydria, and anti-intrinsic factor antibodies.

Hereditary Spherocytosis

The most common congenital hemolytic anemia in Northern European populations, caused by autosomally dominant inherited mutations in erythrocyte membrane proteins (ankyrin, band 3, spectrin) leading to microspherocytes, increased MCHC, and splenic extravascular hemolysis.

Paroxysmal Nocturnal Hemoglobinuria (PNH)

An acquired clonal stem cell disorder resulting from somatic PIG-A gene mutations, leading to a deficiency of GPI-anchored complement-regulatory surface proteins (CD55 and CD59) and causing intravascular hemolysis, pancytopenia, and severe venous thrombosis.

Usual Interstitial Pneumonia (UIP) Pattern

The hallmark radiologic and histopathologic pattern of idiopathic pulmonary fibrosis (IPF), characterized by subpleural, basal-predominant reticular opacities, traction bronchiectasis, and honeycombing with minimal ground-glass attenuation on HRCT.

Pulmonary Langerhans Cell Histiocytosis

An interstitial lung disease occurring almost exclusively in young adult smokers, characterized by granulomatous proliferation of Langerhans cells (Birbeck granules, CD1a+) forming upper-lobe predominant nodules and bizarre-shaped thin-walled cysts with preserved lung volumes.

Lymphangioleiomyomatosis (LAM)

A rare multisystem disease occurring almost exclusively in women of childbearing age, characterized by abnormal smooth muscle proliferation around bronchoalveolar structures, bilateral thin-walled round cysts throughout the lungs, chylothorax, and recurrent pneumothoraces.

Silicosis

A fibrotic pneumoconiosis caused by chronic inhalation of crystalline silicon dioxide ($\text{SiO}_2$), characterized radiographically by small rounded nodules in the upper lung lobes and hilar lymph node enlargement with 'eggshell' calcification.

Chronic Eosinophilic Pneumonia

An idiopathic inflammatory lung disease affecting predominantly middle-aged atopic women, characterized on chest imaging by peripheral, non-segmental alveolar infiltrates sparing the perihilar zones, described as the 'photographic negative of pulmonary edema'.

Sarcoidosis (Bilateral Hilar Lymphadenopathy)

A systemic granulomatous disease characterized by non-caseating epithelioid granulomas, typically presenting on chest radiography as symmetric bilateral hilar and right paratracheal lymph node enlargement (Stage I) accompanied by CD4+ lymphocytic alveolitis.

Löfgren Syndrome

An acute, benign presentation of sarcoidosis characterized by the clinical triad of erythema nodosum, bilateral hilar lymphadenopathy, and migratory polyarthritis (frequently involving the ankles), accompanied by fever.