| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Thorac Cardiovasc Surg 2003;125:1167-1169
© 2003 The American Association for Thoracic Surgery
Brief Communications |
From the Departments of Cardiovascular Surgerya and Cardiology,b Tokyo Women's Medical University, The Heart Institute of Japan, Tokyo, Japan.
Received for publication March 23, 2002. Accepted for publication Aug 28, 2002. Address for reprints: Masato Nakajima, MD, Department of Cardiovascular Surgery, Tokyo Women's Medical University, The Heart Institute of Japan, 8-1 Kawada-cho, Shinjyuku-ward, Tokyo, 162-8666 Japan (E-mail: masato-n{at}zf6.so-net.ne.jp).
Biventricular pacing is currently being explored as a means to improve cardiac function among patients with congestive heart failure. The mechanism of efficacy of this therapy is still unknown, but in patients with left bundle branch block, biventricular pacing resolves ventricular dyssynchrony and ameliorates myocardial wall function. We present a successful aortic valve replacement and biventricular pacemaker implantation for a case of aortic regurgitation with severe left ventricular dysfunction and left bundle branch block.
Clinical summary
A 47-year-old man was referred to our hospital for detailed examination of congestive heart failure. His hemodynamic condition had deteriorated 1 month before, and he required administration of inotropic agents and ventilatory support at another hospital. He gradually recovered from cardiac shock and was transferred to our hospital. On admission, his hemodynamic condition was still unstable, and the chest x-ray film showed cardiomegaly with a cardiothoracic ratio of 66% and massive congestion. Electrocardiography showed complete left bundle branch block with a QRS duration of 202 ms (Figure 1), whereas echocardiography revealed severe aortic regurgitation and left ventricular dilatation and dysfunction (diastolic dimension of 85 mm, systolic dimension of 78 mm, and fractional shortening of 0.10). Preoperative cardiac catheterization showed increased left ventricular end-diastolic pressure (to 18 mm Hg), and left ventriculography revealed a severely dilated and dysfunctional left ventricular end-diastolic volume index of 347 mL/m2, a left ventricular end-systolic volume index of 237 mL/m2, and an ejection fraction of 32%. Aortography revealed severe aortic regurgitation (Sellers IV). The patient was scheduled for aortic valve replacement with resynchronization therapy. The patient and his family were informed of the risks and efficacy of this surgical treatment.
|
|
As an alternative to conventional medical therapy for severe heart failure, biventricular pacing has recently been examined for its ability to improve hemodynamics by resynchronizing the ventricles in patients with intraventricular conduction delays.
1 Several clinical trials for cardiac resynchronization therapy are ongoing, and recent reports suggest the possibilities of acute and long-term hemodynamic improvement. 2-4
In patients with ischemic cardiomyopathy or severe left ventricular dysfunction caused by valvular heart disease, the most important goal is treatment of the ischemic or valvular lesions that are causing myocardial damage. However, the risk of cardiac surgery in such patients still remains high. Therefore, we considered the combined therapy of biventricular pacing with surgical treatment as a perioperative hemodynamic assist system.
At this stage, in our limited experience, we considered that this combination therapy should be indicated in patients with severe left ventricular dysfunction caused by ischemic or valvular heart disease refractory to medical therapy and with major intraventricular conduction block. As indicated, QRS duration was more than 130 ms.
The most effective location for left ventricular pacing is still the subject of controversy. In our case the left ventricular lead was implanted on the midlateral portion during cardiopulmonary bypass. Ideally, the lead should be fixed on the most effective surface from which left ventricular pacing ameliorates the hemodynamic state without cardiopulmonary support, but this was difficult in a patient with a dilated and dysfunctional left ventricle. The leads were passed through the intercostal space and located in the subclavicular position. This technique might be useful for future reimplantation of the pacing lead transvenously.
References
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
