PROGRESS IN CARDIOLOGY
Retrograde left atrial catheterization with a new steerable cardiac catheter Christodoulos Stefanadis, MD, Costas Kourouclis, MD, Costas Stratos, MD, Christos Pitsavos, MD, and Pavlos Toutouzas, MD. Athens, Greece Catheterization of the left atrium, in contrast to the other heart cavities, has presented and still presents a technical problem. Even though retrograde access to the left atrium via the left ventricle has been attempted with special catheters, 1 the inherent difficulties and weaknesses of these methods have meant that, today, the only means of access to the left atrium is via the transseptal route. 2"4 Because of the technical difficulties this route sometimes presents and, in particular, because of the complications it can cause, its use as a diagnostic method is mainly restricted to special cases. 5 However, with the development of invasive therapeutic techniques, particularly percutaneous catheter mitral valvuloplasty, 6 direct access to the left atrium has become more important than ever. 7-11 On the other hand, hemodynamic12,13 and secretory 14' 15 investigations of the left atrium may well make it very important in the near future to have an easy and safe method for catheterization of this heart cavity for the purposes of angiographic, hemodynamic, and biochemical study. Previous research in our laboratory has shown that an externally steerable angiographic catheter can be used successfully in coronary angiography and left ventriculography. TM The design of the catheter described here was based on the same principle but with a view to the achievement of retrograde access to the left atrium via the mitral valve. DESIGN AND CONSTRUCTION OF THE CATHETER SYSTEM
The steerable guiding system was designed by the Dr. Stefanadis and is comprised of the guiding catheter and a second catheter that is introduced into the left atrium. The guiding catheter (Schneider-Shiley From the Department of Cardiology, University of Athens Medical School, Athens. Greece. Received for publication May 8, 1989; accepted Sept. 15, 1989. Reprint requests: C. Stefanadis. MD, Tepeleniou 9, GR 154 52 Paleo Psychico, Athens. Greece. 4/1/17569
AG, European Division, Zurich, Switzerland) is 110 cm long with a diameter of 9F and has a soft tip. The proximal end is connected to a system with two hemostatic valves (Duostat, Advanced Cardiovascular Systems, Inc., Mountain View, Calif.) (Fig. 1, A). A 0.012 inch Teflon-coated stainless steel wire (the steering arm), with a soft flexible tip, is passed through one of these valves and along the inside of the catheter. It emerges 6 cm from the distal end of the catheter and is fastened to the catheter wall 1.7 cm from the tip (Fig. 1; B,C,D). The proximal end of the steering arm is attached to a plastic rod. The other hemostatic valve is used for the introduction of the second catheter (i.e., the atrial catheter [AC]), which is inserted through the guiding catheter to the left atrium. The AC catheter (Schneider-Shiley, transfusion, high flow) is made of polyurethane and is 130 cm long with a diameter of 3.4F (Fig. 2). Before this study was performed, this catheter was tested in vitro and was found to have satisfactory flow characteristics. Also, the complete retrograde catheterization system was used in a preliminary in vivo test on two patients during conventional transseptal catheterization for mitral balloon valvuloplasty and was found to give the same results for left cavity pressures and ~ransmitral gradient. CATHETERIZATION TECHNIQUE
The steerable guiding catheter is introduced through a sheath to the right femoral artery and then, with the aid of a 0.038 inch guide wire, through the descending aorta, aortic arch, and ascending aorta to the left ventricle. After the intravenous administration of 7500 IU heparin to the patient, the steering arm is retracted, which causes the catheter tip to bend into an arc of approximately 160 degrees (Fig. 3). The catheter is now rotated counterclockwise, which brings the tip to a position below the mitral valve orifice. The placement of the catheter tip is confirmed by reference to the left anterior oblique and right anterior oblique angiographic projections (Fig. 4 A, B). The free flexion of the catheter tip (be375
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American Heart Journal
Fig. 1. The proximal (A) and distal (B,C,D) ends of the guiding catheter (GC). After retraction of the steering arm (SA) and tightening of the hemostatic valve (V), the tip changes its configuration from straight to sharply curved.
Fig. 2. The distal end of the guiding catheter (GC). The guide wire (GW), (A), and atrial catheter (AC), (B), may be introduced through the guiding catheter.
fore it is fixed in position by tightening of the hemostatic valve) may be taken as a sign that the guiding catheter has not become entangled with the chordae tendineae or the papillary muscles. The second, narrower catheter, with a 0.025 inch 3 guide wire, is now introduced through the guiding catheter until it is 5 to 6 cm from the tip of the latter. The guide wire is advanced until it emerges from the tip of the guiding catheter. With careful manipulation of its distal end and, when necessary, minor adjustments to the steering arm of the guiding catheter, it is then advanced into the left atrium (Fig. 5 A). The free movement of this wire in and out of the atrium is tested to ensure that there is no entanglement with the subvalvular apparatus. The guiding catheter is now withdrawn slightly and fixed in its final position with its tip in the mitral valve orifice. Finally, the AC catheter is advanced along the guide wire until it too enters the left atrium (Fig. 5, B), whereupon the guide wire is removed. The AC catheter may now be used to record atrial blood pressure. The guiding catheter (after its tip i s placed in the left ventricular cavity) may be used to record left ventricular pressure at the same time (Fig. 6). In this position the guiding catheter does not interfere with blood flow t h r o u g h the mitral valve. When the measurements are completed, the AC catheter is withdrawn, the steering arm is loosened, and the steerable guiding catheter is removed through the femoral artery sheath.
Number 2, Part
Retrograde left atrial catheterization
MV Fig. 3. Schematic representation of approach to the left atrium. After the guiding catheter (GC) is introduced into the left ventricle, the steering arm (SA) is retracted, and the tip of the guiding catheter may be positioned below the mitral valve (MV). It is then easy to introduce the atrial catheter (AC) into the left atrium (LA) along a d guide wire.
B Fig. 4. Radiographic frames during the approach to the mitral valve orifice in left anterior oblique (A), and right anterior oblique, (B), projections.
Table I. Patient data and hemodynamic findings
L VP (ram Hg) Disease CAD MS
No. of patients
LAP (mm Hg) (mean)
MVG (mm Hg)
Catheterization time (rnin)
12 (9 M, 3F) 8 (2 M, 6 F)
52-64 ( m e a n 57 _+ 3) 53-67 ( m e a n 58 _+ 4)
125 __ 18
12 _+ 4
11 _+ 5
105 _+ 24
6 -+ 4.2
20.5 _+ 4.5 (P C W P 21.3 _+ 4 mmHg, mean)
15 _+ 2.8
1 + 0.1
5-8 ( m e a n 6.1 _+ 2) 6-11 ( m e a n 7.5 _+ 3)
CAD, Coronary artery disease; MS, mitral stenosis; LVP, Left ventricular pressure; LAP, left atrial pressure; MVG, mitral valve gradient; MVA, mitral valve area; PCWP, pulmonary capillary wedge pressure.
We tested the above technique in 20 patients (11 men, 9 women) after completion of the normal catheterization procedure. The patients' ages range from 52 to 67 years (mean, 57.8 years). Twelve patients had coronary artery disease, and eight had mitral stenosis. Temporary cardiac pacing was available as a protective measure for the duration of the proce-
dure. We performed left ventriculography in the right anterior oblique projection to check mitral valve function after catheterization in all cases. In cases of mitral stenosis, complete right and left heart catheterization was used to determine the pulmonary artery pressures, the pulmonary capillary wedge pressure, the left ventricular pressure, and the mitral valve gradient. The latter measurements
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ture ventricular beats were observed during the catheterization, but no sustained arrhythmias were recorded either during or after the procedure. The left ventriculography that was recorded after catheterization, compared with the routine ventriculography that was recorded before catheterization, showed no indications of mitral valve dysfunction. COMMENTS
B Fig. 5. Successive radiographic frames during the approach to the left atrium (right anterior oblique projection). A, Introduction to the guide wire (GW) to the left atrial cavity; B, The atrial catheter (AC), which has been introduced into the left atrium, has been advanced co a pulmonary vein. SA, steering arm.
served as a check of the accuracy of the left atrial pressure and mitral valvel gradient readings obtained with the new catheter. Cardiac output was evaluated with the thermodilution method. Mitral valve area was calculated with the Gorlin formula. All patients gave their informed consent to the procedure. OBSERVATIONS
Patient data and hemodynamic findings are shown in Table I. Catheterization of the left atrium was performed successfully in all cases. Two different physicians performed the procedure in 12 and 8 cases, resepctively. The mean time taken for the entire procedure (approach to the left atrium, pressure readings, and removal of the catheter) was 6.1 minutes. For the eight patients with mitral stenosis, the mean time was 7.5 minutes. No complications arose either during the procedure or during subsequent hospitalization. Prema-
Retrograde catheterization of the left atrium via the left ventricle presents great technical difficulties 1, 5 that arise as a result of the position of the mitral ring relative to the left atrial cavity. To approach the mitral orifice, the catheter must bend through a large angle. Apart from this, the mitral subvalvular system itself impedes access to the left atrium. A catheter for retrograde left atrial catheterization, invented by Earl Shirey 1 in 1968, did not catch on, probably because it was unsuccessful in many cases, particularly in patients with mitral stenosis. A recent technique for mitral valvuloplasty, by means of retrograde atrial catheterization with a preformed catheter that was tested in three patients, also has some disadvantages. 10First, it is not known how frequently it will be possible to enter the left atrium with a preformed catheter. Second, it is possible that the preshaped catheter may be passed between the chordae tendineae or papillary muscle, which could result in damage to the subvalvular system during the procedure. The inability to achieve a controlled approach to the mitral valve and, through it, to the left atrium, has led to the universal adoption of the transseptal approach for left atrial catheterization. 7,8 This method requires greater experience on the part of the operator and may be accompanied by serious complications. The mortality rate in some specialized centers can reach 0.1% The factors mentioned here mean that diagnostic application of left atrial catheterization must be restricted to a small number of special cases, 5 although the method is widely used today for percutaneous mitral valvuloplasty.6, 9, 11 This latter technique is of increasing interest, and the results are encouraging) 7 The complications that are sometimes observed are mainly related to the transseptal approach to the left atrium. 6 Apart from these clinical considerations, the need for direct access to the left atrium is becoming more crucial with the rekindling of interest in the function 13 and secretory capacity 15 of this heart cavity. A simple method for retrograde catheterization of the left atrium would thus be desirable. We designed our new guiding catheter with this aim. Its basic design principle is the same as that of a multipurpose
Retrograde left atrial catheterization
Number 2, Part 1
angiographic catheter that was designed and tested in our clinic.16The configuration of the distal end of the guiding catheter may be altered by remote control, and the catheter tip may thus be positioned precisely beneath the mitral orifice, which allows easy access to the left atrium. Testing of the free movement of the guiding catheter and guide wire below and within the mitral valve ensures that there is no entanglement with the subvalvular apparatus. The materials from which the catheter is constructed are considered safe and are widely used in invasive cardiology. The effectiveness of this system was confirmed by our clinical tests, in which entry into the left atrium was easily achieved in all patients, even in those with mitral stenosis (Fig. 6). In patients with mitral stenosis, measurements of pulmonary wedge pressure and mitral valve gradient before retrograde catheterization were in agreement with atrial pressure and mitral valve gradient measurements obtained with the new system, which indicates that the latter measurements were accurate and that the retrograde insertion of the catheter to the left atrium had no noticeable effect on the mitral valve pressure gradient. (For measurements of ventricular pressure, the guiding catheter tip is lowered into the left ventricle by means of the steering arm so that it does not interfere with the blood flow through the mitral valve.) These findings, together with those of our preliminary in vitro and in vivo tests, suggest that the new system is reliable for the simultaneous measurement of atrial and ventricular pressures. The advantages of this system are clear. It provides an alternative to the transseptal route and avoids complications due to damage to the interatrial septum or free wall of the heart, 5 It allows the simultaneous recording of atrial and ventricular pressures and thus the easy determination of the transmitral pressure gradient. It is quick and easy and does not require great experience on the part of the operator. Although we observed no complications in our patients, further testing with a larger series of patients with different heart diseases will be necessary to establish that the method is indeed universally simple and complication-free. Also, it may be found that in some cases catheters of different dimensions may be necessary to make the technique effective. Considering that the operators had no previous experience with the technique, we believe that our results to date indicate that after some refinement of the method and equipment, this new catheter system has the potential to be successful in all but a few extreme cases. We believe that this system will provide valuable in retrograde mitral valvuloplasty and the direct inves-
Liill I' i! , l l , ii i
Fig. 6. Simultaneous recording of left ventricular pressure (L VP) via the guiding catheter and left atrial pressure (LAP) via the atrial catheter in a patient with mitral stenosis.
tigation of left atrial function, secretory capacity, and electrophysiology. SUMMARY
A new type of guiding catheter that may be used for retrograde transmitral catheterization of the left atrium is described. The catheter has a 9F diameter and incorporates a steering arm by means of which the catheter tip may be made to curve through an arc of 0 to 180 degrees, entirely through external manipulation. In this way the tip of the guiding catheter may be positioned below the mitral valve orifice and used for the introduction of a smaller catheter into the left atrial cavity. We tested the system in 20 patients, eight of whom had mitral stenosis. Left atrial catheterization was successful in all cases, and no difficulties were encountered in entry of the left atrium, nor were there any complications during or after the procedure. The technique will provide useful in the study of left atrial function (hemodynamic, electrophysiologic, secretory). It may also be helpful in percutaneous mitral valvuloplasty by permitting retrograde, rather than transseptal, access to the left atrium.
1. Shirey E K , Sones F M Jr. R e t r o g r a d e t r a n s a o r t i c a n d mitral valve catheterization. A m J Cardiol 1966;18:745-53. 2. Ross J Jr. T r a n s s e p t a l left h e a r t catheterization: a new m e t h o d of left atrial p u n c t u r e . A n n Surg 1959;149:395-401.
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3. Cope C. Technique for transseptal catheterization of the left atrium: preliminary report. J Thorac Surg 1959;37:482-6. 4. Ross J Jr. Considerations regarding the technique for transseptal left heart catheterization. Circulation 1966;34:391-9. 5. Balm DS, Grossman W. Percutaneous approach and transseptal catheterization. In: Grossman W, ed. Cardiac catheterization and angiography. Philadelphia: Lea and Febiger, 1986:71-5. 6. Lock JE, Khalilullah M, Shrivastavas S, Bahl V, Keane JF. Percutaneous catheter commisurotomy in rheumatic mitral stenosis. N Engl J Med 1985;313:1515-18. 7. Mullins CE. Transseptal left heart catheterization: Experience with a new technique in 520 pediatric and adult patients. Ped Cardiol 1983;4:239-45. 8. O'Keefe JH Jr, Vliestra RE, Hanley PC, Seward JC. Revival of the transseptal approach for catheterization of the left atrium and ventricle. Mayo Clin Proc 1985;60:790-5. 9. Babic UU, Pejcic P, Djurisic Z, Vucini M, Grujicic SM. Percutaneous transarterial balloon valvuloplasty for mitral valve stenosis. Am J Cardiol 1986;57:1101-4. 10. Orme EC, Wray RB, Mason JW, Balloon mitral valvuloplasty via retrograde left atrial catheterization. AM HEART J 1989;117:680-3.
11. Zaibag MA, Kasab SA, Ribeiro PA, A1Fagih MR. Percutaneous double-balloon mitral valvotomy for rheumatic mitral stenosis. Lancet 1986;1:757-61. 12. Ross J Jr, Braunwald E, Morrow AG. Transseptal left atrial puncture: a new method for the measurement of left atrial pressure in man. Am J Cardiol 1959;3:653-5. 13. Boudoulas H, Barrington W, Wooley C. Left atrial dynamics in mitral stenosis [Abstract]. Circulation 1988;78(suppl 4): II471. 14. DeBold JA, Borenstein HB, Veress AT, Sonnenberg HB. A rapid and patent natriuretic response to intravenous injection of atrial myocardial extract. Life Sci 1981;28:89-94. 15. Cantin M, Genest J. The heart and the atrial natriuretic factor. Endocrinol Rev 1985;6:107-26. 16. Stefanadis C, Kourouklis C, Kallikazaros J, Gavaliatsis I, Pitsavos C, Papadopoulos P, Toutouzas P. A multipurpose steerable catheter for left-sided cardiac catheterization. Am J Cardiol 1989;63:147-9. 17. McKay RG. Balloon vatvuloplasty for treating pulmonic, mitral and aortic valve stenosis. Am J Cardiol 1988;61:102G-8G.
Geographic variation in sudden coronary death R i c h a r d F. Gillum, MD.
Cardiac a r r e s t out of hospital is a major unsolved p r o b l e m in the p r e v e n t i o n a n d m a n a g e m e n t of coron a r y h e a r t disease. Such arrests are usually fatal. 1 T o t a l c o r o n a r y m o r t a l i t y varies considerably a m o n g the states, b u t little is k n o w n a b o u t geographic variation in c o r o n a r y m o r t a l i t y out of the hospital. 2 Deaths a t t r i b u t e d to ischemic h e a r t disease occurring out of hospital or in e m e r g e n c y rooms have been used as an indicator of s u d d e n coronary d e a t h from fatal cardiac arrest, a' 4 This r e p o r t describes variations in coronary d e a t h s o u t of hospital or in emergency rooms a m o n g 42 states in 1984 to 1986. P l a c e of d e a t h . Using d a t a from the National Center for H e a l t h Statistics (NCHS), deaths were enum e r a t e d for several cause-of-death categories by
From the National Center for Health Statistics. Received for publication Aug. 14, 1989; accepted Sept. 22, 1989. Reprint requests: Richard F. Gillum, MD, Office of Analysis and Epidemiology, National Center for Health Statistics, Center Building, Room 2-27, 3700 East West Highway, Hyattsville, MD 20782. 4/i/17568
place of d e a t h and b y status of d e c e d e n t when d e a t h Occurred in a hospital or medical center. 5 T h e s e d a t a on place of d e a t h were obtained from two items t h a t a p p e a r on the U n i t e d States S t a n d a r d Certificate of Death: I t e m 7c: " H o s p i t a l or other institution n a m e (if n o t in either give street a n d n u m b e r ) " ; I t e m 7d: " I f hospital or institution indicate DOA, O P / E m e r g e n c y R o o m (ER), inpatient (specify)." For the period 1984 to 1986, 43 states provided d a t a to N C H S for b o t h of these items. One state (Connecticut) was excluded because of a large percentage of d e a t h s with missing d a t a on patient status. Therefore, this report is limited to d a t a from the 42 states with complete data. For these states, 185 (0.1%) of records coded to ischemic heart disease for white males were excluded from analyses due to missing hospital or patient status data. For no state was the p e r c e n t more t h a n 2.4. Deaths were t a b u l a t e d by the state of residence r a t h e r t h a n the state of death, since in m o s t cases b o t h will be the same, since risk of d e a t h from chronic diseases is usually related to long-term risk factors prevailing in resident populations, a n d since emer-