The Cardiovascular System

The heart beats roughly one hundred thousand times a day and pushes blood through some sixty thousand miles of vessels, and the language built around that machinery is the language you will hear most often at the bedside. Cardiovascular vocabulary dominates emergency triage, telemetry units, operating rooms, cardiac rehabilitation and nearly every medication list you will ever reconcile. It is also, mercifully, one of the most decodable vocabularies in medicine: a compact set of roots names the heart, its layers, its chambers, its valves and its vessels, and the suffixes you learned in Chapters 2 and 3 bolt onto them with almost no irregularity. Once cardi/o, angi/o, arteri/o, phleb/o, ather/o and thromb/o are secure, a phrase such as percutaneous transluminal coronary angioplasty stops being a wall of syllables and becomes a sentence. This chapter builds that habit root by root, then carries it through pathology, diagnostics, surgery, drug-class suffixes and the abbreviations that fill a real chart.

Section 1The Heart: Layers, Chambers and Valves

Two roots for one organ: cardi/o and coron/o

The Greek root cardi/o does nearly all the clinical work. It appears in the diagnosis (cardiomyopathy), the procedure (cardiac catheterization), the specialty (cardiology), the drug class (cardiotonic) and the emergency (cardiac arrest). Note the adjective ending: standing alone, the root takes -ac rather than -al, giving cardiac, not “cardial.” That small ending is worth memorizing because it recurs in iliac and celiac. Treat this as usage rather than a rule. The adjectives built on the -cardium layer nouns take -al: endocardial, myocardial (from the combining form my/o, muscle — a combining form, not a prefix), epicardial and pericardial. But -ac survives in other prefixed forms, as the position table below shows with intracardiac, and likewise in extracardiac.

The Latin root coron/o means crown, and it names the arteries that encircle the heart like a crown resting on a head. Coronary therefore does not mean “of the heart” in general — it means “of the vessels that feed the heart muscle.” Coronary artery disease is a disease of those specific vessels, and that precision matters when you are reading a chart that also mentions valve disease or heart failure, neither of which is coronary in origin.

Build a term to feel the machinery working. Cardi/o + megaly = heart + enlargement, so cardiomegaly (kar-dee-oh-MEG-ah-lee) is an enlarged heart. Cardi/o + my/o + pathy = heart + muscle + disease, so cardiomyopathy (kar-dee-oh-my-OP-ah-thee) is disease of the heart muscle itself. Tachy- + cardia = fast + heart condition, giving tachycardia (tak-ih-KAR-dee-ah), and brady- + cardia = slow + heart condition, giving bradycardia (brad-ih-KAR-dee-ah). Four terms, one root, and you did not memorize a single one of them as a whole word.

Three layers, three prefixes

The heart wall is a three-layer sandwich, and each layer is named by a prefix you already know attached to cardi. Working from the inside out: endo- + cardi + um = within + heart + structure, the endocardium (en-doh-KAR-dee-um), the smooth lining in contact with blood. My/o + cardi + um = muscle + heart + structure, the myocardium (my-oh-KAR-dee-um), the thick contractile middle layer. Epi- + cardi + um = upon + heart + structure, the epicardium, the thin outer layer that hugs the heart surface.

Outside all three sits the pericardium (per-ih-KAR-dee-um), from peri- meaning around: a tough double-walled sac holding roughly 15 to 50 milliliters of lubricating fluid. Now decode the diseases and they name themselves. Endo/card/itis is inflammation of the inner lining and its valves, classically from bacteria seeding a damaged valve. Myo/card/itis (my-oh-kar-DYE-tis) is inflammation of the muscle, often viral, and it can drop the pumping strength of an otherwise healthy young heart within days. Peri/card/itis (per-ih-kar-DYE-tis) is inflammation of the surrounding sac and produces the sharp, positional chest pain that eases when the patient leans forward.

Fluid collecting inside that sac is a pericardial effusion. If it accumulates fast enough to squeeze the heart and prevent filling, the result is cardiac tamponade (tam-pon-AHD), a term borrowed from the French for plugging a wound. The treatment is named just as literally: pericardi/o + centesis = pericardium + surgical puncture to withdraw fluid, or pericardiocentesis (per-ih-kar-dee-oh-sen-TEE-sis). Notice that you now understand a life-threatening emergency and its rescue procedure entirely from word parts.

Chambers, septa and the direction of flow

The heart has four chambers: two thin-walled receiving chambers called atria and two thick-walled pumping chambers called ventricles. Atrium (AY-tree-um) is Latin for an entrance hall, and it takes the -um to -a plural, so two of them are atria (AY-tree-ah) — never “atriums.” The same rule governs septum to septa, ostium to ostia and bacterium to bacteria. Ventricle means little belly and gives the combining form ventricul/o.

The dividing walls are septa: the interatrial septum between the atria and the interventricular septum between the ventricles. A hole in either is a septal defect, abbreviated ASD or VSD, and the word tells you the anatomy without a diagram. Blood flows in one direction only, and four valves enforce it. Between right atrium and right ventricle sits the tricuspid valve (three cusps). Between left atrium and left ventricle sits the mitral (MY-tral) valve, also called the bicuspid valve because it has two cusps; the name comes from its resemblance to a bishop’s mitre. Guarding the exits are the two semilunar valves, so called for their half-moon cusps: the pulmonary valve into the pulmonary artery and the aortic valve into the aorta.

Valves fail in exactly two ways, and the vocabulary is symmetrical. A valve that will not open fully is stenotic, from sten/o meaning narrow, giving aortic stenosis (steh-NOH-sis). A valve that will not close fully leaks backward, described as regurgitation or insufficiency, giving mitral regurgitation. A valve whose cusps balloon backward into the atrium is said to prolapse, hence mitral valve prolapse (MVP). Turbulent flow across any of these produces a murmur, and the chart will describe when in the cycle it occurs: systolic during contraction, diastolic during filling.

Electrical timing is carried by named structures, several of them eponyms. The sinoatrial (SA) node in the right atrium is the natural pacemaker; the atrioventricular (AV) node delays the signal so the atria can empty; the bundle of His (HISS) and the Purkinje (pur-KIN-jee) fibers carry it into the ventricles. Modern texts increasingly write “atrioventricular bundle” for the bundle of His, part of a broad shift away from possessive eponyms, but both forms remain in active clinical use and you should recognize each.

One warning about ventricul/o before you leave this section: it lives in two organs. The heart has two ventricles; the brain has four. Ventriculography can therefore mean imaging of a cardiac chamber or of the cerebral ventricles, and a ventriculoperitoneal shunt has nothing to do with the heart at all. Context resolves it every time — a partner root such as cardi/o means the pump, while encephal/o, hydrocephalus or neurosurgery means the brain. You will meet the neurologic sense again in Chapter 13.

Section 2Vessels, Circulation and Blood Pressure

The vessel roots: angi/o, vas/o, arteri/o, ven/o, phleb/o

Vessels have a general root and several specific ones. Angi/o is the Greek word for vessel and covers any of them, which is why angiography can image an artery, a vein or a graft. Vas/o and vascul/o are the Latin equivalents; vas/o shows up in physiology and pharmacology (vasoconstriction, vasodilation, vasopressor) while vascul/o shows up in adjectives and diagnoses (vascular, vasculitis). Be aware that vas/o can also mean duct in a non-cardiac context: a vasectomy removes a segment of the vas deferens, not a blood vessel, which you will meet in Chapter 12.

Arteries carry blood away from the heart and take the root arteri/o; their smallest branches are arterioles, using the diminutive ending -ole. Veins carry blood toward the heart and have two roots, Latin ven/o and Greek phleb/o; their smallest tributaries are venules, using the diminutive -ule. As with bone in Chapter 6, the Latin form owns the anatomy and the Greek form owns the pathology: you will chart a venipuncture and an intravenous line, but you will read a diagnosis of phlebitis (fleh-BYE-tis) and an order for a phlebotomy. The largest artery is the aorta, root aort/o; the largest veins are the superior and inferior venae cavae.

Notice that arteries and veins are defined by direction, not by oxygen. The pulmonary artery carries deoxygenated blood away from the right ventricle to the lungs, and the pulmonary veins carry oxygenated blood back to the left atrium. Students who learn “artery equals red” get the pulmonary circuit backwards every time, and it matters when you are interpreting a congenital defect or a pulmonary embolism.

Decoding built vessel terms

Work through a few deliberately. Angi/o + plasty = vessel + surgical repair or reshaping, so angioplasty (AN-jee-oh-plas-tee) is a procedure that reopens a narrowed vessel. Put the full clinical name together and every word earns its place: percutaneous transluminal coronary angioplasty is per- (through) + cutane/o (skin) + trans- (across) + lumin/o (the lumen) + coronary (the heart’s own arteries) + angioplasty (vessel reshaping) — a repair of a coronary artery performed through the skin and along the inside of the vessel. That is the whole of PTCA, decoded.

Two more. Angi/o + oma = vessel + tumor, giving angioma, a benign vascular growth; add hem/o (blood) for hemangioma (hee-man-jee-OH-mah), the strawberry-colored lesion you will see on infants. Thromb/o + phleb + itis = clot + vein + inflammation, giving thrombophlebitis (throm-boh-fleh-BYE-tis), an inflamed vein with a clot in it. Note also anastomosis (ah-nas-toh-MOH-sis), a connection between two vessels, whether natural (collateral circulation) or surgical (the graft junctions in a bypass).

Two vein words deserve special attention because they are constantly confused. A varix is a single enlarged, tortuous vein; several are varices. The adjective is varicose, as in varicose veins, and the combining form is varic/o. Meanwhile varic/o also produces varicocele (VAR-ih-koh-seel), where -cele means hernia or swelling — a mass of dilated veins in the scrotum. Same root, two very different clinical pictures, and the suffix is what separates them.

Blood pressure, perfusion and the words that describe them

The heart cycle has two halves, and both terms end in a syllable students routinely mispronounce. Systole (SIS-toh-lee) is contraction; diastole (dye-ASS-toh-lee) is relaxation and filling. Their adjectives shift the stress: systolic (sis-TOL-ik) and diastolic (dye-ah-STOL-ik). A blood pressure of 128/76 reports the systolic pressure over the diastolic pressure, and the gap between them is the pulse pressure.

The instrument is a sphygmomanometer (sfig-moh-mah-NOM-eh-ter), which decodes cleanly once you know sphygm/o means pulse: pulse + man/o (pressure, thin) + -meter (instrument for measuring). The suffix -tension means pressure, so hypertension is high blood pressure and hypotension is low blood pressure. Orthostatic hypotension uses orth/o (straight, upright) and describes the pressure drop on standing that makes patients dizzy and falls-prone.

Delivery of blood to tissue is perfusion. When it fails, the tissue signs are named just as directly: cyanosis (sye-ah-NOH-sis) from cyan/o (blue) is the bluish discoloration of poor oxygenation; pallor is paleness; edema (eh-DEE-mah) is swelling from fluid in the tissues; and delayed capillary refill is the bedside test. Claudication (klaw-dih-KAY-shun), from the Latin for limping, is the cramping leg pain on walking that signals arterial insufficiency; charted in full as intermittent claudication, it is one of the cardinal symptoms of peripheral artery disease.

Section 3The Language of Cardiovascular Disease

Blocked flow: ischemia, infarction and the clot words

Ischemia (is-KEE-mee-ah) is built from isch/o, meaning to hold back or suppress, plus -emia, meaning blood condition: blood held back from a tissue. It is a description of supply, and it is reversible. Infarction is what happens when ischemia goes on long enough that the tissue dies; the dead area itself is the infarct. A myocardial infarction (MI) is therefore death of heart muscle, and its parts are my/o + cardi + al = muscle + heart + pertaining to, plus infarction. Necrosis, from necr/o meaning death, is the general word for tissue death and appears in the pathology report that follows.

The obstruction itself has its own vocabulary. A thrombus (THROM-bus) is a clot that forms and stays where it formed; the process is thrombosis, and the root is thromb/o. An embolus (EM-boh-lus) is anything that travels through the bloodstream and lodges somewhere distant — a broken-off clot, but also fat, air or amniotic fluid; the event is an embolism, and the root is embol/o. A clot in a deep leg vein is a deep vein thrombosis (DVT); if a fragment breaks free and lodges in the lung, that is a pulmonary embolism (PE). Same clot, two words, and the difference is whether it moved.

An artery can also fail by bulging rather than blocking. An aneurysm (AN-yoo-rizm) is a localized dilation of a weakened arterial wall; an abdominal aortic aneurysm is charted as AAA and spoken as “triple A.” If the wall tears and blood tracks between its layers, that is a dissection. If it bursts, the suffix -rrhexis (rupture) names the event and -rrhage or -rrhagia (bursting forth of blood) names the bleeding. Hemorrhage (HEM-or-ij) is hem/o + rrhage = blood + bursting forth.

Pump failure and the rhythm words

Heart failure (HF, historically CHF for congestive heart failure) means the heart cannot move blood forward well enough to meet the body’s demand. The consequences follow the plumbing, and so does the vocabulary. Left-sided failure backs blood up into the lungs and produces pulmonary edema, dyspnea (DISP-nee-ah, difficult breathing), orthopnea (or-THOP-nee-ah, orth/o + -pnea = upright + breathing, meaning breathlessness when lying flat) and paroxysmal nocturnal dyspnea (PND). Right-sided failure backs blood up into the body and produces peripheral edema, jugular venous distention (JVD), hepatomegaly and ascites (ah-SYE-teez, fluid in the abdomen). Right-sided failure caused by lung disease has its own Latin name, cor pulmonale (kor pul-moh-NAL-ee) — cor being Latin for heart.

How well the left ventricle empties is expressed as the ejection fraction (EF), the percentage of blood pushed out with each beat. A chart may read HFrEF (heart failure with reduced ejection fraction) or HFpEF (heart failure with preserved ejection fraction), and the distinction changes the entire treatment plan. Related terms include preload (the filling volume), afterload (the resistance the ventricle pumps against) and cardiac output (CO), the volume ejected per minute.

Rhythm disorders are called arrhythmias or, more precisely, dysrhythmias. Decode both: a- means without and rhythm/o means rhythm, so arrhythmia literally says “no rhythm”; dys- means bad or difficult, so dysrhythmia says “abnormal rhythm,” which is usually the more accurate description. Fibrillation is chaotic, quivering activity; atrial fibrillation (AF or AFib) is the common chronic version and a major stroke risk because blood pools and clots in the quivering atrium. Ventricular fibrillation (VF) is a cardiac arrest rhythm. Flutter is also rapid, but unlike fibrillation it is organized and regular. Asystole (ay-SIS-toh-lee) is a- + systole = without + contraction, a flat line. A premature ventricular contraction (PVC) is an early extra beat, and palpitations is the patient’s word for feeling them.

Congenital, peripheral and inflammatory disease

Congenital heart defects are named by their anatomy, which makes them unusually readable. An atrial septal defect (ASD) and a ventricular septal defect (VSD) are holes in the walls you met in Section 1. Patent ductus arteriosus (PDA) uses patent meaning open: a fetal vessel that should close after birth stays open. Coarctation of the aorta is a congenital narrowing of the aorta, classically just beyond the aortic arch, and coarctation comes from the Latin for pressing together. Tetralogy of Fallot (fal-OH) is an eponym describing four defects occurring together — tetra- meaning four — and is one of the eponyms that has survived because no descriptive substitute is shorter.

Away from the heart, peripheral artery disease (PAD, sometimes charted as PVD for peripheral vascular disease) is atherosclerosis of the limb arteries, and it produces claudication, cool skin, hair loss over the shins and slow-healing ulcers. Raynaud phenomenon (ray-NOZE) is episodic vasospasm of the digits with color change. Varicose veins and chronic venous insufficiency produce the opposite picture — warm, swollen, brown-stained ankles — and telling arterial from venous disease by the wording of an assessment note is a genuinely testable skill.

Inflammatory and infectious cardiovascular disease rounds out the list. Vasculitis is inflammation of vessel walls. Rheumatic heart disease follows untreated streptococcal pharyngitis and damages valves years later. Infective endocarditis seeds bacteria onto valve surfaces. And pericarditis, which you decoded in Section 1, closes the loop: inflammation of the sac around the heart, sometimes progressing to effusion and tamponade.

Section 4Assessment, Imaging and Laboratory Terms

Bedside assessment vocabulary

Before any machine is involved, the assessment itself has a vocabulary. Auscultation (aws-kul-TAY-shun) is listening with a stethoscope; palpation is feeling with the hands. The normal heart sounds are written S1 and S2, the “lub” of the atrioventricular valves closing and the “dub” of the semilunar valves closing. Extra sounds are charted as S3 and S4 and are collectively described as a gallop. A murmur is turbulent flow across a valve; a palpable murmur is a thrill; and a bruit (BROO-ee, from the French for noise) is turbulent flow heard over an artery, most often the carotid.

The apical pulse is auscultated at the apex of the heart, roughly the fifth intercostal space at the midclavicular line, which is also where the point of maximal impulse (PMI) is felt. Intercostal decodes as inter- + cost/o + -al = between + rib + pertaining to. Peripheral pulses are graded and named by their artery: radial, brachial, femoral, popliteal, dorsalis pedis and posterior tibial. Charting a pulse as “absent” versus “thready” versus “bounding” is descriptive language a clinician will act on directly.

Electrical and ultrasound studies

The electrocardiogram (ECG, also EKG from the German Elektrokardiogramm) decodes as electr/o + cardi/o + -gram = electrical + heart + record. Its waves have names you will see quoted in notes: the P wave is atrial depolarization, the QRS complex is ventricular depolarization, and the T wave is ventricular repolarization. The ST segment matters enormously in practice, because ST elevation defines a STEMI (ST-elevation myocardial infarction) as opposed to an NSTEMI (non-ST-elevation myocardial infarction). Continuous monitoring on a hospital unit is telemetry, from tele- (distant) + -metry (measurement). A portable 24-hour recorder is a Holter monitor, an eponym still in universal use.

Ultrasound studies use echo- (reflected sound) or son/o (sound). Echocardiography (ek-oh-kar-dee-OG-rah-fee) images the moving heart with sound waves and reports chamber size, wall motion, valve function and ejection fraction. A transthoracic echocardiogram (TTE) is performed through the chest wall; a transesophageal echocardiogram (TEE) passes the probe down the esophagus for a closer view of the valves and atria, decoding as trans- + esophag/o + -eal = across + esophagus + pertaining to. Doppler ultrasound adds flow direction and velocity, and a duplex scan combines Doppler with anatomic imaging — the standard study for a suspected DVT.

Stress testing evaluates the heart under demand, either by treadmill or by pharmacologic agent, and may be paired with imaging as a nuclear stress test or stress echocardiogram. A cardiac catheterization threads a catheter from a radial or femoral artery into the coronary circulation; injecting contrast during it produces a coronary angiogram, which remains the reference standard for defining where a blockage sits. Non-invasive alternatives include CT angiography (CTA), magnetic resonance angiography (MRA) and the coronary calcium score. For veins, venography (also called phlebography) images the deep venous system, and the ankle-brachial index (ABI) compares ankle to arm pressures to quantify peripheral arterial disease.

The laboratory values on a cardiac chart

Blood tests carry their own shorthand, and most of them are decodable or at least learnable in a single pass. Troponin is a protein released when myocardial cells die, so a rising troponin is the biochemical confirmation of an MI; older markers such as CK-MB (creatine kinase, myocardial band) appear in historical charts. BNP or NT-proBNP (B-type natriuretic peptide) rises when ventricular walls are stretched and is used to sort cardiac from pulmonary causes of dyspnea. D-dimer is a fragment of broken-down fibrin and is used to help rule out DVT and PE.

The lipid panel reports total cholesterol, LDL (low-density lipoprotein, the fraction that deposits in artery walls), HDL (high-density lipoprotein, the fraction that carries cholesterol away) and triglycerides. Elevated results are charted with the suffix you already know: hyperlipidemia and hypercholesterolemia, both built on -emia. Anticoagulation is monitored with PT/INR (prothrombin time and international normalized ratio) and aPTT (activated partial thromboplastin time). Electrolytes matter too, because hyperkalemia (hyper- + kal/i + -emia = high + potassium + blood condition) and hypokalemia both provoke dangerous dysrhythmias.

Section 5Procedures, Drug Endings and Chart Abbreviations

The surgical suffixes in cardiovascular context

You met the surgical suffixes in Chapter 2, and the cardiovascular system exercises nearly all of them. -otomy is an incision, -ectomy is removal, -ostomy is the creation of a new opening, -plasty is surgical repair or reshaping, -rrhaphy is suturing, -pexy is surgical fixation, -centesis is puncture to withdraw fluid and -lysis is breaking down or freeing. Applied here they generate a working operative vocabulary in a few minutes.

Angi/o + plasty gives angioplasty, widening a narrowed vessel with a balloon, usually followed by placement of a stent, a small mesh scaffold that holds the vessel open. Valvul/o + plasty gives valvuloplasty, repair of a stenotic valve. Endarterectomy (end-ar-ter-EK-toh-mee) decodes as end- + arter + ectomy = within + artery + removal, the surgical stripping of plaque from the inner lining of an artery, most commonly the carotid. Atherectomy shaves the plaque itself; thrombectomy removes a clot; embolectomy removes a traveling clot from where it lodged; aneurysmectomy resects a ballooned segment. Thromb/o + lysis gives thrombolysis, dissolving a clot with a drug rather than a blade.

Larger operations combine the pieces. Coronary artery bypass graft (CABG, spoken aloud as “cabbage”) routes blood around a blocked coronary using a saphenous vein or internal mammary artery, and each junction is an anastomosis. Valve disease may be treated by replacement with a mechanical or bioprosthetic valve, or by transcatheter aortic valve replacement (TAVR), decoding as trans- (across) + catheter + the valve named. Rhythm disorders may be treated by catheter ablation (destruction of the misfiring tissue), by a pacemaker for rates that are too slow, or by an implantable cardioverter-defibrillator (ICD) for rhythms that are lethal. Cardioversion is a timed shock that converts an organized but abnormal rhythm; defibrillation is an untimed shock for fibrillation; and cardiopulmonary resuscitation (CPR) supports both circulation and breathing when neither is present.

Drug classes you can recognize by their endings

Generic drug names are assigned with class-specific stems, which means a whole medication list becomes decodable. A name ending in -olol (metoprolol, atenolol, propranolol) is a beta blocker, slowing rate and reducing myocardial demand. A name ending in -pril (lisinopril, enalapril) is an ACE inhibitor; one ending in -sartan (losartan, valsartan) is an angiotensin receptor blocker. A name ending in -dipine (amlodipine, nifedipine) is a dihydropyridine calcium channel blocker. A name ending in -statin (atorvastatin, simvastatin) lowers LDL cholesterol. A name ending in -parin (heparin, enoxaparin) is an anticoagulant of the heparin family.

Descriptive class names decode just as cleanly. A vasodilator widens vessels; a vasopressor raises pressure by constricting them; an antihypertensive lowers blood pressure; a diuretic increases urine output and reduces volume; an antiarrhythmic stabilizes rhythm; a cardiotonic such as digoxin strengthens contraction; and a nitrate such as nitroglycerin dilates coronary vessels to relieve angina. The prefix anti- means against and does most of the work in this list.

“Blood thinner” is a lay term that covers three different drug classes, and the distinction is worth holding onto. An anticoagulant (heparin, warfarin, apixaban) interferes with the clotting cascade. An antiplatelet (aspirin, clopidogrel) stops platelets from clumping. A thrombolytic or fibrinolytic (alteplase) actively dissolves a clot that has already formed. In an acute STEMI it is the alternative when timely catheter treatment (PCI) is not available; in acute ischemic stroke it is first-line for eligible patients within the treatment window, with catheter thrombectomy added on top for a large-vessel occlusion rather than substituted for it. None of them literally thins blood, and confusing them on a medication reconciliation is a patient safety problem, not a vocabulary quibble. Decode the endings instead: anti- plus coagul/o means against clotting, while thromb/o plus -lytic means clot-dissolving.

Abbreviations on a real chart

Cardiovascular notes are dense with abbreviations, and most are simply first letters of terms you can already decode. Read the table below as a decoding exercise rather than a memorization list: PCI is percutaneous coronary intervention, and you already know that percutaneous means through the skin and coronary means the heart’s own arteries. One caution: some abbreviations are ambiguous or discouraged. PVD may mean peripheral vascular disease or posterior vitreous detachment; MS may mean mitral stenosis or multiple sclerosis; and MI has meant both myocardial infarction and mitral insufficiency. When an abbreviation could plausibly mean two things, write the term out.

Words worth knowing