Age: 31
Gender: Female
Occupation: Salesperson
Working diagnosis: Palpitations
HISTORY
The patient was first noted to have a murmur at age 6 years. The murmur was felt to be a “functional murmur,” and no echocardiogram was performed.
She was active in sports during adolescence and had no functional limitations.
She came to medical attention at age 31 because of two episodes of tachycardia. Each episode lasted for 15 seconds and was not associated with syncope. She did not feel overly stressed, had no symptoms of heat or cold intolerance, and did not drink more than one caffeinated beverage a day.
Comments: A young woman presenting with palpitations is common in any adult cardiology clinic. Some associations such as mitral valve prolapse are common, but in many cases, no cardiac abnormalities are found. The subsequent workup should look for clues of structural heart malformations, such as evidence of atrial enlargement or valvular abnormalities. Although the history of a childhood murmur is suspicious, innocent murmurs in children are common.
PHYSICAL EXAMINATION
BP 102/68 (in the right arm), HR 80 bpm (regular), oxygen saturations 99% on room air
Height 163 cm, weight 48 kg, BSA 1.5 m 2
Surgical scars: None
Neck veins: The JVP was normal with a normal venous waveform.
Lungs/chest: Clear to auscultation
Heart: There were no heaves or thrills. The first heart sound was normal. There was a fixed split second heart sound. The pulmonary component of the second heart sound was normal. At the apex, there was a midsystolic click followed by a grade 2/6 mid-to-late systolic murmur. There were no diastolic murmurs.
Abdomen: There was no evidence of hepatosplenomegaly.
Extremities: There was no pedal edema.
Comments: The midsystolic click followed by the mid-late systolic murmur is diagnostic of mitral valve prolapse. A fixed split second heart sound strongly suggests an ASD.
Notably absent findings in this case include a loud pulmonary component of the second heart sound suggestive of idiopathic pulmonary hypertension, which can affect younger women and lead to RA enlargement and arrhythmia. The right heart was not palpable, making a significant left-to-right shunt less likely. There was no evidence of left heart failure.
ELECTROCARDIOGRAM
FINDINGS
Heart rate: 95 bpm
QRS axis: +95°
QRS duration: 104 msec
Coronary sinus or low atrial rhythm with inverted P-waves in the inferior leads, and an RSR’ pattern was in lead V1 with a modest persistent S-wave to V6
24-hour Holter monitor: Predominantly “atrial” rhythm with an average heart rate of 78 bpm. Rare isolated premature supraventricular complexes.
Comments: Inverted P-waves in the inferior leads can indicate lead misplacement or an ectopic atrial pacemaker. In the setting of an ASD, such P-waves suggest a sinus venosus defect. The P-wave axis makes interpretations about atrial size from this ECG difficult. The incomplete RBBB and rightward axis are suspicious for RV hypertrophy. The borderline right axis deviation and 3-mm R-wave suggest RV volume (rather than pressure) overload.
In this patient, the abnormal P-wave forces turned out to be a red herring.
CHEST X-RAY
FINDINGS
Cardiothoracic ratio: 43%
Comments: The normal CXR offers strong evidence against pulmonary hypertension. RV hypertrophy is not confirmed, but cannot be excluded.
