三心房心例における右房ペーシングの血行動態に及ぼす影響—手術前・後における検討

Hemodynamic response to right atrial pacing in a patient with cor triatriatum:Pre- and post-operative studies

　三心房心は，1868年Church^1），により初めて報告され，1956年Lewis^2）とVineberg^3）が外科的治療に初めて成功した。本邦では1962年の新井^4）の報告以来現在まで，私どもが調べえた範囲では43例の報告があるが^5〜7），成人例は少数である。しかも，三心房心の血行動態に関して詳細に検討された報告はみられない。

　このたび我々は三心房心の1成人例において，外科手術前後で行った右房ペーシング負荷の血行動態に及ぼす影響について検討し，興味ある知見が得られたので文献的考察を加え報告する。

A 34-year-old man with cor triatriatum, who com-plained of palpitation and dizziness during atrial flut-ter, was admitted to our hospital for further cardiac evaluation.

Sign and symptom of congestive heart failure were clinically absent, as long as maintained normal sinus rhythm.

The hemodynamic responses of left ventricular function to atrial pacing were evaluated before and after surgery.

The pacing rate was gradually increased up to 140/min. At control state, pulmonary arterial wedge pres-sure (PAWP), pulmonary arterial pressure, left ven-tricular systolic pressure (LVSP), left ventricular enddiastolic pressure (LVEDP) and cardiac output (CO) were all within normal limits. As heart rare increased, LVSP, LVEDP and CO were decreased, and mean PAWP was increased from 17 mmHg to 36 mmHg, and the pressure gradient (PAWP-LVEDP) was increased from 3 mmHg to 31 mmHg.

After surgery, these abnormal hemodynamic res-ponses to atrial pacing were normalized.

From these findings, it is shown that the patients with cor triatriatum even without any sign or symp-tom of congestive heart failure may develop abnor-mal hemodynamic responses as heart rate increases.

The present studies, therefore, indicate that atrial pacing is useful in evaluating subclinical hemodyna-mic abnormalities in patients with cor triatriatum as in those with mitral stenosis.