Age: 19 years
Gender: Female
Occupation: Waitress
Working diagnosis: Ventricular septal defect
HISTORY
The patient originally presented at 2 weeks of age with heart failure and a murmur. A perimembranous VSD was diagnosed on echocardiography, and she responded well to medical treatment with diuretics and digoxin. The VSD partially closed spontaneously, and medication was ceased at 18 months of age. The patient thrived and had regular follow-up during her childhood.
Three years ago (16 years old) she reported breathlessness on exercise with an associated cough. She had had several admissions with wheezing and had a strong family history of atopy. An echocardiogram showed that the perimembranous VSD was still present with a left-to-right ventricular pressure gradient of 66 mm Hg and no evidence of volume loading of the left heart. Exercise stress testing was normal. Following this assessment, she did not attend further follow-up appointments.
She is a smoker.
Comments: VSD is the most common congenital heart defect (2 out of 1000 live births), representing more than 30% of cardiac malformations. However, more than 50% of patients undergoing surgery for a primary VSD have an associated lesion, either congenital or acquired.
Patients with small defects may never need intervention, and, for this reason, it is tempting to discharge them from follow-up. Nevertheless, continued surveillance may be useful for the detection of acquired complications including aortic regurgitation, unexpected left ventricular volume loading, subaortic fibromuscular stenosis (see Case 21 ), or RVOT obstruction (3%–10% of cases). Of note, in adults, the RVOT is often difficult to image and the associated obstructive lesion may be missed.
CURRENT SYMPTOMS
The patient presented again at 19 years of age, when she was 16 weeks pregnant, with increasing dyspnea on exertion, having to sit down to catch her breath after climbing two flights of stairs. She experienced exertional palpitations but denied chest pain, syncope, or ankle swelling.
NYHA class: II
Comments: The presence of worsening symptoms should alert the physician to the development of other problems. Although pregnancy itself may precipitate dyspnea, symptom onset in early gestation is suspicious of underlying hemodynamic compromise. Signs suggestive of important right ventricular outflow obstruction in patients with a VSD include cyanosis as well as exertional fatigue and dyspnea.
PHYSICAL EXAMINATION
BP 110/70 mm Hg, HR 95 bpm, oxygen saturation 98%
Height 147 cm, weight 52 kg, BSA 1.46 m 2
Surgical scars: None
Neck veins: JVP was elevated to 4 cm above the sternal angle with a prominent A-wave.
Lungs/chest: Chest was clear.
Heart: There was an RV lift with a palpable thrill at the upper left sternal edge. A grade 4 ejection systolic murmur was heard at the upper left sternal edge in addition to a softer holosystolic systolic murmur lower down the sternal edge. The ejection systolic murmur relatively obscured the holosystolic murmur. Peripheral pulses were normal.
Abdomen: A gravid uterus was palpable.
PERTINENT NEGATIVES
There was no peripheral edema, clubbing, RV third or fourth heart sounds, or hepatomegaly.
Comments: Oxygen saturations were normal, indicating either a left-to-right shunt or no significant shunt.
In pregnancy, the central venous pressures may be increased due to volume loading. However, in this patient the waveform was abnormal suggesting raised RV end-diastolic pressure and RV hypertrophy. The absence of a prominent CV-wave implied that any tricuspid regurgitation was insignificant or chronic.
A loud, harsh ejection systolic murmur, peaking in intensity near midsystole and loudest in the mid to upper left precordium, is characteristic of a double-chambered RV. The auscultatory characteristics of the VSD are determined by its location in relation to the RV cavity obstruction. If the VSD opens into the high-pressure proximal chamber, the “VSD” murmur may be softer or absent.
LABORATORY DATA
| Hemoglobin | 11.3 g/dL (11.5–15.0) |
| Hematocrit | 33% (36–46) |
| MCHC | 33.5 g/dL (32–36) |
| MCV | 91 fL (83–99) |
| Platelet count | 280 × 10 9 /L (150–400) |
| Sodium | 136 mmol/L (134–145) |
| Potassium | 3.5 mmol/L (3.5–5.2) |
| Creatinine | 0.63 mg/dL (0.6–1.2) |
| Blood urea nitrogen | 2.7 mmol/L (2.5–6.5) |
Comments: Red cell mass increases in a linear fashion throughout pregnancy; however, plasma volume expands more rapidly, producing a decline in hemoglobin concentration, hematocrit, and red cell count, particularly during the second trimester (see also Case 75 ). The mean corpuscular hemoglobin concentration remains constant. These physiological changes in oxygen carrying capacity may become more significant when cardiac reserve is limited. The relatively low hemoglobin was also consistent with the absence of a resting or exercise-induced right-to-left shunt.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 95 bpm
PR interval: 158 msec
QRS axis: +106°
QRS duration: 62 msec
There was sinus rhythm with prominent P-waves in I and II, which were also peaked in V2 and V3 (right atrial overload). The QRS axis was deviated to the right. There were dominant, almost pure R-waves in V4R and V1.
Comments: The electrocardiogram showed a right dominant picture with RA overload, right-axis deviation, and RV hypertrophy, as suggested by the dominant R-waves in V4R and V1. These abnormalities cannot be explained by a small VSD, where the ECG would be normal. The RV hypertrophy suggests important RVOT obstruction in the absence of pulmonary hypertension.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
