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Tetralogy of Fallot

A case study and billing and coding perspective using the 2021 updated fee schedule

Chase, Julia R. DNP, RN-BC; Fliehman, Maci BSN, RN; LeGal, Michael DNP, RN, CCRN-K; Spicer, Whitney BS, BSN, MS; Rogers, Julia L. DNP, RN, CNS, FNP-BC

Author Information
doi: 10.1097/01.NPR.0000827112.13673.80
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Tetralogy of Fallot (TOF) is a cardiac anomaly that includes a combination of four defects: ventricular septal defect, overriding aorta, pulmonary stenosis, and right ventricular hypertrophy.1,2 TOF is the most common cyanotic congenital heart defect and represents approximately 5% to 10% of all congenital heart diseases (CHD).2 The etiology of most CHD remains unknown; however, prenatal, environmental, and other genetic factors place a fetus at risk for developing TOF. Factors such as maternal alcohol and drug use, advanced maternal age, exposure to teratogens in utero, exposure to maternal infections, infants with low birth weight or who are small for gestational age, and genetic defects can cause CHD.2 The purpose of this article is to guide healthcare providers in the identification, treatment, and billing of TOF in the outpatient primary care settings.

Case study presentation


An 18-month-old male patient presents to the office with his mother to establish care after recently moving to a rural area. Previous medical records, lab results, diagnostic imaging, and immunizations are obtained and reviewed, a process that took 10 minutes (see Hematology results at age 9 months).3 The patient is up-to-date on vaccinations, which he received at the local health department; however, the patient has not been seen by a pediatrician or healthcare provider since age 9 months.

Past medical history

His mother reports that the patient was born at the 10th percentile for his height and weight and had a “small heart murmur” that was expected to correct itself after birth.

Allergies: Penicillin.

Medication: None

Family history:

Mother: Alive; age 42; employed full-time as dental hygienist; medical history: Grave's disease diagnosed January 2021; benign left breast mass 2019; started consuming alcohol as a teenager and continued to drink a glass of wine per day until quitting during her second trimester; pregnancy: conception through artificial insemination; hyperemesis gravidarum requiring I.V. fluid infusions to prevent dehydration; vaginal delivery at home with a midwife, no complications at birth.

- Hematology results at age 9 months
Lab Test Result Normal Values3
Hemoglobin 15.7 g/dL ↑ 9.5-14.0 g/dL
Hematocrit 45% ↑ 29%-43%
Red blood cell count 7.2 x 106/mcL ↑ 3.5-5.2 x 106/mcL
  1. Capillary blood gas:

  2. pH

  3. PaO2

  1. 7.3 ↓

  2. 35 mm Hg ↓

  1. 7.31-7.41

  2. 40-50 mm Hg

Lactate (venous) 2.5 mmol/L ↑ 0.6-2.2 mmol/L
  1. PT: 10 seconds ↓

  2. INR: 0.8

  1. PT: 11.0-12.5 seconds

  2. INR: 0.8-1.1

PTT 26 seconds ↓ 30.0-40.0 seconds
Blood glucose 84 mg/dL 60-100 mg/dL
NT-proBNP 149 pg/mL ↑ 0-100 pg/mL
Note: Normal reference ranges vary between labs. Some or all are age-dependent.
↑ = above upper limit of normal; ↓ = below lower limit of normal; PaO2 = partial pressure of oxygen; PT/INR = prothrombin time/international normalized ratio; PTT = partial thromboplastin time; NT-proBNP = N-terminal pro b-type natriuretic peptide

Father: Donor; age 30; not present in child's life. Records report no history of cancer or heart disease personal or familial.

Social History: Lives with mother; household is nonsmoking and pet-free; attends day care full-time Monday through Friday; high-fiber diet and 48 oz of liquids (water or juice) per day; sleeps 9 hours per night with two 1-hour naps during the day.

History of present illness

History obtained from patient's mother who is a reliable source of information.

Patient gets “winded and breathes rapidly then squats down and lips turn blue.”

Onset: First noticed changes 3 months ago; more severe in the last month.

Location: Generalized–fatigue; cardiovascular–murmur at birth; pulmonary–lips turning blue.

Quality/severity: The episodes are happening more frequently and increasing in severity.

Modifying factors: Symptoms occur when the patient is drinking, playing, or walking to the park. Patient squats down one to three times during walks to the park (six blocks away from home), which seems to relieve the tachypnea. Mother initially suspected constipation, and increased dietary fiber and fluid intake, but behavior has not changed.

Associated signs and symptoms

Mother reports increased fatigue. Denies symptoms of abdominal pain.

Review of systems

General: (-) fever; (+) fatigue; (-) weight loss; (+) prolonged feedings

Neurologic: (-) confusion

Head, eyes, ears, nose, and throat (HEENT): (+) lip cyanosis

Cardiovascular: (-) chest pain

Pulmonary: (+) dyspnea on exertion

Gastrointestinal: (+) constipation occasionally–normal bowel movement every 3 days

Genitourinary: (+) 4-6 wet diapers in 24 hours

Musculoskeletal: (+) normal range of motion in all extremities

Skin: (+) cool; (-) pale; (+) diaphoretic–after play

Objective findings

Vital signs: Temperature: 96.9° F (36.1° C), heart rate: 110, respirations: 24 breaths/min, BP: 136/88, SpO2: 95% on room air.

Height: 31” (78.7 cm) (between 10th and 25th length-for-age growth percentile), weight: 23.5 lb (10.7 kg) (near 25th weight-for-age growth percentile).

General: No acute distress, well kempt.

Neurologic: Cranial nerves II-XII grossly intact; awake, alert, oriented x 4 (person, place, time, situation); pupils equal, round, reactive to light (PERRL); deep tendon reflexes 2+.

HEENT: Head normocephalic, atraumatic, normal hair distribution; PERRL; oropharynx with moist mucous membranes, pink; neck soft, nontender, no lymphadenopathy.

Cardiovascular: Normal S1 and S2 with regular rate and rhythm; 3/6 harsh systolic crescendo-decrescendo murmur along the left sternal border radiating to the left axilla and back, no rub, no gallop; no peripheral edema.

Pulmonary: Breathing even and unlabored on room air; clear to auscultation bilaterally upper and lower lobes anteriorly and posteriorly; decreased oxygen saturations with exertion from 95% down to 88%.

Gastrointestinal: Abdomen is round, soft, nontender, nondistended; bowel sounds hyperactive x 4 quadrants.

Musculoskeletal: Equal strength bilateral upper and lower extremities; moves all extremities appropriately.

Skin: Pink, warm, and dry except after activity when the patient becomes diaphoretic and develops central cyanosis (noted on lips), and circumoral cyanosis; clubbing of bilateral fingernail beds.

Differential diagnosis

Failure to thrive, central cyanosis, systolic crescendo-decrescendo murmur, polycythemia, chronic hypoxia, asthma, pulmonary hypertension, lactic acidosis, congenital cardiac anomaly.


Referral to Pediatric Cardiologist: Appointment made for this afternoon.

Diagnostics (labs/imaging): Complete blood cell count, basic metabolic panel, venous blood gases, coagulation profile, ECG, echocardiogram, and chest X-ray.

Medications: Oxygen as needed for SpO2 <90% and/or during hypercyanotic (tet) spells.

Education: Diagnosis of TOF, hypercyanotic spells and interventions, repair of congenital abnormality, oxygen (as prescribed).3-5

Follow-Up: Follow-up recommended with a primary care provider annually with a focused history, physical exam, and a 12-lead ECG to assess cardiac rhythm and evaluate QRS duration.3,6 Follow-up with pediatric cardiologist at least once a year including an annual echocardiogram until age 10, then echocardiography is recommended every 2 years through adulthood.4 A cardiac MRI is also indicated every 36 months in stable patients.5

Time spent with patient and mother was 65 minutes. Medical decision-making, the complexity of the problem, and the risk of complications are high, while the complexity of data reviewed is considered moderate.

Coding evaluation and management

The Centers for Medicare and Medicaid Services (CMS) made changes effective January 1, 2021, to the Physician Fee Schedule Payment for Office/Outpatient Evaluation and Management (E/M) visits, which is reflected in the Current Procedural Terminology (CPT®) codes 99202 through 99205 for new patients and 99212 through 99215 for established patients. CPT® codes are numerical codes used to identify the E/M medical services provided for providers to receive reimbursement for services. The 1995/1997 E/M documentation guidelines had three main components: history, exam, and medical decision-making (MDM). Additional documentation elements include time, counseling, coordination of care, and nature of presenting problem.7 The new 2021 guidelines eliminate history and physical (H&P) exam as coding criteria and reflect the ability for a provider to select the level of office visit using either total time or MDM.8 The H&P components are still important to document, and may be required for clinical practice, professional liability, and quality measurement, but are no longer the sole focus in code selection.9

- 2021 CPT® codes based on time and MDM level8
New Patient CPT Codes Time (in minutes) Level of MDM Complexity or Number of Problems Addressed Complexity of Data Reviewed Risk of Complications, Morbidity, and Mortality
99202 15-29 Straightforward Minimal Minimal or None Minimal
99203 30-44 Low Low Limited Low
99204 45-59 Moderate Moderate Moderate Moderate
99205 60-74 High High Extensive High
Established Patient CPT Codes Time (in minutes) Level of MDM Complexity or Number of Problems Addressed Complexity of Data Reviewed Risk of Complications, Morbidity, and Mortality
99212 10-19 Straightforward Minimal Minimal or None Minimal
99213 20-29 Low Low Limited Low
99214 30-39 Moderate Moderate Moderate Moderate
99215 40-54 High High Extensive High
Appropriate time must be documented in the medical record.
CPT, Current Procedural Terminology; MDM, medical decision-making


According to the 2021 guidelines, time alone may be used to select the appropriate E/M codes (99202-99215). Each of the codes have a specified time range and includes face-to-face and non-face-to-face time personally spent by the provider on the day of the encounter. Specific service descriptors are used when time is used for reporting E/M service codes (see 2021 CPT® codes based on time and MDM level).8 Time should only reflect the time the provider spent with the patient on the one focused problem (for example, 22 minutes) and exclude staff time.10 Time includes the following activities when performed: preparing to see the patient (for example, review of records); obtaining and/or reviewing separately obtained history; performing a medically appropriate exam; counseling and education; ordering medications, tests, or procedures; referring and communicating with other healthcare professionals; documenting clinical information in the health record; independently interpreting results and communicating results to the patient/family/caregiver; and care coordination. The following time should not be counted: performance of other services that are reported separately, travel, or general education on health. When the NP individually provides a face-to-face or non-face-to-face patient encounter along with a physician (known as a shared or split visit), the appropriate E/M code is determined based on the total amount of time spent between the two providers separately.11 For example, if the APRN spends 20 minutes with the patient and then the physician spends 15 minutes with the patient, the total amount of billable time is 35 minutes. It is important for all NPs to bill under their unique National Provider Identifier (NPI) number and not bill as incident to or split/shared using the physician's NPI. While billing incident to or split/shared under the physician's NPI creates more revenue, it does not reveal the performance of NPs, which ultimately affects the evaluation and any bonus for NPs based on relative value units.

Medical decision-making

MDM reflects the complexity involved in assessing the presenting problem, establishing a diagnosis, and determining the appropriate management. The practitioner that bills based on the MDM coding method relies on three categories: (1) problems (the severity of the patient's conditions presented at the visit), (2) data (what was reviewed for the visit), and (3) risk (the patient's morbidity or mortality odds).8,10 To qualify for a level of MDM, two of the three elements for that level must be met or exceeded.

The provider must document a detailed explanation in the patient record as to how the patient's plan of care was developed based on the assessment, evaluation of risk for patient management, and review of records and diagnostic testing. Documentation should also include any components that affect the complexity of the visit, such as the influence of social determinants of health.9 Treatment options considered, but not utilized, should also be documented.

In this case study, MDM can be assessed by following a linear progression of thought to get to the diagnosis. The patient was born at the 10th percentile; his weight and growth curves are currently on target. Mother's use of alcohol during pregnancy could have contributed to the patient's low birth weight; however, cardiac anomalies can also cause low birth weight.2,12 The patient has prolonged feedings and snacks throughout the day. There are several clinical manifestations (dyspnea on exertion, decreased oxygen saturations, and diaphoresis on exertion) reflective of pulmonary involvement (for example, asthma, chronic obstructive pulmonary disease, restrictive lung disease, or respiratory muscle weakness).13 The symptoms can also be a compensatory mechanism (from hypoxia or acidosis), can result from pulmonary vasculopathies (for example, pulmonary hypertension), or can occur from psychological conditions.13 The patient has central cyanosis and clubbing of his nail beds. These clinical signs can be indicative of chronic hypoxemia and related to pulmonary disease or cardiac right-to-left shunts.2 The child squats after activity, which is a compensatory mechanism used by older children to alleviate hypercyanotic spells.2

What does not align with the pulmonary diagnosis is the patient's “small heart murmur” that was detected at birth and has evolved into a grade 3/6 harsh systolic crescendo-decrescendo murmur. While heart murmurs in newborns and children are common and generally innocent, some heart murmurs are caused by structural problems of the heart such as septal defects, cardiac shunts, and stenotic heart valves.14

Analysis of the previous hematology results from age 9 months reveals elevated hemoglobin, hematocrit, red blood cell count, and lactate. The capillary blood gas showed a decrease in the partial pressure of oxygen (PaO2) and pH, which means the patient's oxygenation and tissue integrity need to be monitored. Continued blood gas abnormalities may result in need for increased oxygen support and immediate intervention and contribute to increased risk of complications. These diagnostic abnormalities add polycythemia secondary to cyanosis to the list of differential diagnoses. Patients with chronic hypoxemia compensate through erythropoiesis which is evidenced by increased hemoglobin and hematocrit levels such as those found in the patient's hematology workup.2 The patient had an elevated lactate level on the previous labs, which is indicative of decreased oxygen perfusion to the tissues and is considered a marker for tissue hypoxia.15 Taking this into consideration, adding to the list of differential diagnoses is a possible cardiac anomaly. The N-terminal pro b-type natriuretic peptide (NT-proBNP) test showed that it was significantly elevated, which is associated with increasing right ventricular hypertrophy. This finding prompts the ordering of an ECG, chest X-ray, and echocardiogram.13 The patient's previous ECG revealed a right bundle-branch block and a right ventricular hypertrophy strain pattern.16 The chest X-ray showed an irregular, boot-shaped appearance of the heart with the apex turning upwards, and the echocardiogram report revealed: (1) membranous ventricular septal defect with a right-to-left shunt, (2) severe pulmonic valve stenosis with an obstruction, (3) severe right ventricular hypertrophy, and (4) overriding aorta.16,17 Therefore, based on the patient's history, exam, and diagnostic results, the diagnosis is a CHD, specifically TOF. The level of MDM is high because the complexity of problems is high, the complexity of data reviewed is moderate to extensive, and the risk of complications is high; therefore, the most appropriate CPT code to bill is a 99205.

In addition to making the diagnosis, other considerations within this case study leading to billing a 99205 include the treatment plan. Pharmacologic treatments, follow-up diagnostics, and referrals for patients with TOF are based on several factors specific to the patient, severity of illness, age, and disease process. In this case, a prescription for oxygen, as needed, could be provided for low SpO2 (<90%) and/or during a hypercyanotic spell.5 Beta-blockers may be appropriate and can help relax the right ventricular outflow tract and improve blood flow, which are especially important when patients have hypercyanotic spells.5 It is recommended that the NP refer the patient to a pediatric cardiologist who specializes in congenital heart abnormalities due to a suspected diagnosis of TOF.

Implications for practice

Caring for complex medical conditions in the rural primary care setting can present challenges and rewards. NPs need strong assessment skills to recognize key signs and symptoms of impaired cardiac function including growth on the lower side of normal, which is indicative of a child's overall health status.18 To help promote an optimal long-term outcome for the patient, the NP can provide education, obtain baseline data, order diagnostic tests, and make referrals. As the patient ages, providing primary, secondary, and tertiary care prevention strategies decreases the risk of comorbidities associated with CHD.19 One challenge is reducing the barriers to accessing care for physical needs, immunizations, dental care, and lab work as well as care and resources for mental well-being. The health of patients with CHD living in rural communities can be improved by overcoming these barriers.

The Physician Fee Schedule was updated in 2021 by the CMS. This case study on TOF can guide NPs in appropriate documentation and E/M coding practices based on the new guidelines, which include selecting office visit codes using time or MDM. The newest change from the 1995/1997 guidelines to the 2021 guidelines is the elimination of documentation requirements of a defined number of components within the review of systems and the exam. While it is still important to document key elements within the H&P, it is no longer the sole focus in code selection.9 Instead, time and MDM are key components in determining the appropriate code. Each clinical practice site, professional liability service, and quality management service can have specified requirements for documentation and billing practices, so it is important to know the regulations of individual practices.


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15. Bhardwaj V, Kapoor PM, Irpachi K, Ladha S, Chowdhury UK. Basic arterial blood gas biomarkers as a predictor of mortality in Tetralogy of Fallot patients. Ann Card Anaesth. 2017;20(1):67–71. doi:10.4103/0971-9784.197839.
16. Alkashkari W, Al-Husayni F, Almaqati A, AlRahimi J, Albugami S. An adult patient with a Tetralogy of Fallot case. Cureus. 2020;12(11). doi:10.7759/cureus.11658.
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18. Hueckel R. Pediatric patients with congenital heart disease. J Nurse Pract. 2019;15(1):118–124.
19. LaBrocca SM, Angosta AD. Management of an adult patient with congenital heart disease: implications for the advanced practice registered nurse. Home Health Care Manag Pract. 2016;28(1):3–8.

advanced practice; billing; coding; pediatric congenital heart disease; Tetralogy of Fallot

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