**5. Surgical treatment**

Surgery is indicated in patients undergoing elective cardiac surgery that have symptomatic AF or those with asymptomatic AF with low operative risk.34 It is advised that patients with persistent or permanent AF scheduled for elective cardiac surgery should be considered for concomitant ablation procedure that may increase both short-term and long-term freedom from AF, in addition to lowering the risk of thromboembolism and improving long term survival and cardiac function35. Surgery for lone AF may be considered in certain circumstances where patients have failed to respond to catheter ablation or in whom catheter ablation is contraindicated such as a mural thrombus. Patients that develop tachycardia-induced cardiomyopathy will also benefit from surgery. It results in atrial or ventricular dysfunction as a result of increased heart rates in an otherwise structurally normal heart.36 If left untreated it can lead to heart failure and is reversible if sinus rhythm is

A key concept in understanding the development of persistent atrial fibrillation is that the atria undergo electrical remodelling. Atrial electrical remodelling results in shortening of the atrial refractory period, myocyte calcium overload, decreased conduction velocity, dispersion of conduction and increased sensitivity to catecholamines4,20,21,22. This phenomenon may be reversed after maintenance of sinus rhythm23. The more a patient experiences AF, the more susceptible they are to continue fibrillating as a result of remodelling. Therefore AF can become a self-sustaining arrhythmia once atrial remodelling has occurred. Micro-reentrant triggers are then no longer necessary and limited to pulmonary venous impulse-triggering sites.24 Therefore, treatment for persistent or

longstanding AF directed at the pulmonary veins only is likely to be unsuccessful.

When pharmacological intervention is unsuccessful or contraindicated in patients, nonpharmacological therapy may be attempted. These include synchronised electrical cardioversion, catheter based ablation techniques or surgical intervention.25,26,27. Directcurrent cardioversion differs from defibrillation whereby the shock is synchronised to the R wave in the patient's ECG. The patient must be adequately anticoagulated during electrical cardioversion in order to prevent disruption of a pre-existing intra cardiac thrombus which will cause it to embolize to the brain or systemic circulation. The risks of electrical cardioversion include hypotension, bradycardia, pulmonary oedema, systemic embolization, skin burns and ventricular arrhythmias.28 Risks of emboli range from 0.5% to 3% and is further multiplied in patients who experience recurrence and treated with serial

Catheter based ablation techniques were initially developed following Cox's pioneering work with the Maze procedure. These techniques were further influenced by research that demonstrated ectopic foci surrounding pulmonary veins. Isolation of the pulmonary veins remains the cornerstone of most AF catheter ablation procedures. Following heparinization, a percutaneous catheter placed into the femoral vein is advanced to the right atrium. The left atrium is accessed via an interatrial septal puncture. Lesions are created around the pulmonary veins using cryoenergy or radio-frequency energy. These techniques have shown a higher success in treating patients with paroxysmal AF compared to those with enlarged left atrium and persistent or permanent AF.31,32 Complications of catheter ablation

Surgery is indicated in patients undergoing elective cardiac surgery that have symptomatic AF or those with asymptomatic AF with low operative risk.34 It is advised that patients with persistent or permanent AF scheduled for elective cardiac surgery should be considered for concomitant ablation procedure that may increase both short-term and long-term freedom from AF, in addition to lowering the risk of thromboembolism and improving long term survival and cardiac function35. Surgery for lone AF may be considered in certain circumstances where patients have failed to respond to catheter ablation or in whom catheter ablation is contraindicated such as a mural thrombus. Patients that develop tachycardia-induced cardiomyopathy will also benefit from surgery. It results in atrial or ventricular dysfunction as a result of increased heart rates in an otherwise structurally normal heart.36 If left untreated it can lead to heart failure and is reversible if sinus rhythm is

include cardiac tamponade, atrioesophageal fistula and stroke33

**4. Non pharmacological therapy** 

cardioversions.29,30

**5. Surgical treatment** 

restored.37 In addition patients in whom anticoagulation is contraindicated may also be suitable candidates that may benefit from surgical intervention following failure of catheter based ablation. Patients that continue to experience thromboembolic events despite adequate anticoagulation may also benefit from surgery.38

Several procedures were developed in the 1980s aimed at finding a cure to atrial fibrillation. Hoewever, most of these procedures were subsequently abandoned due to their inability to address all three of the detrimental sequelae of AF. Early attempts at surgical treatment of AF attempted to isolate and confine AF to a specific region of the atria and thereby stopping it from propagating its effects upon the ventricles. The left atrial isolation procedure developed by Williams and colleagues was successful in confining AF to the left atrium and thus restoring sinus rhythm to the rest of the heart.39 It also removed two of the 3 detrimental consequences attributed to AF namely, irregular heart rate and compromised haemodynamics. The latter was achieved because restoring sinus rhythm on the right side permitted a normal right-sided cardiac output that was delivered to the left side of the heart. The left ventricle responded to the normal cardiac output on the right side by delivering a normal cardiac output. Since the left atrium continued to fibrillate this procedure did not reduce the risk of thromboembolism. The 'Corridor' procedure was introduced in 1985 that isolated a strip of atrium that contained both the SA node and AV node from the rest of the atria to create a continuous pathway (corridor) directing the impulses from the SA node to the AV node to maintain sinus rhythm. Since parts of the right and left atrial were free to fibrillate it did not eliminate the risk of thromboembolism and nor did it restore atrioventricular synchrony.

Cox and colleagues described a series of experiments that attempted to cure AF in dogs. A single incision across both atria successfully prevented AF and atrial flutter. Further investigations by Cox and colleagues led to the Cox-Maze procedure in 1987.16,17,40 The procedure itself was based upon a cut and sew technique whereby multiple incisions were made in the atria. This created lines of scar that interrupted the conduction routes of the most common re-entrant circuits, thus preventing AF or atrial flutter by directing the sinus node impulses along a specified route. It was based around the concept of a maze and as a result was called the Cox-Maze procedure. In contrast to the previous surgical techniques, this was the first that addressed all three sequelae of AF and restored sinus rhythm, AV synchrony and thus significantly reducing the risk of thromboembolism and stroke.41 The original procedure, known as Cox-Maze I was complicated with a high incidence of heart block requiring pacemaker implantation. It also resulted in the late incidence of two problems. Firstly it led to the frequent inability of patients to generate an appropriate sinus tachycardia and secondly left atrial dysfunction. This was modified to the Cox Maze II procedure which despite decreased incidence of conduction system injury was technically difficult. It was therefore modified to the Cox-Maze III procedure that was associated with a higher incidence of sinus rhythm and improved long-term sinus node function and atrial transport function.40 In this procedure several dead-end "alleyways "create a maze-like pathway and permit the depolarization of all the atrial tissue. The Cox Maze III procedure can be performed both through median sternotomy as well as a partial lower sternotomy. The patient is fully heparinized and the surgeon cannulates the patient for cardiopulmonary bypass after dividing the sternum. Bicaval cannulation is achieved. The right atrial appendage is excised and a series of incisions are made to the right atrium including a cryolesion. The aorta is occluded preparing for the left atrial portions of the operation. Cold blood potassium cardioplegia is administered via retrograde perfusion of the coronary

Surgery for Atrial Fibrillation 263

Pulmonary vein isolation is only an ideal choice for those who have new onset paroxysmal AF Lesions can be created using a variety of different approaches that include beating heart epicardial techniques or on pump endocardial approaches that use energy devices or the cut and sew technique. Pulmonary vein isolation can be achieved through either a single lesion encircling all pulmonary veins or two lesions encompassing the left and right pulmonary veins. Left atrial lesion sets are advised in patients with recent-onset or paroxysmal AF undergoing elective surgery with no justification to open the right atrium. This includes pulmonary vein isolation with the addition of linear lesions extending to the mitral annulus and left atrial appendage that is usually excised or excluded. This is because more than 90% of left atrial thrombi originate from the left atrial appendage in patients with non-rheumatic AF.58 Biatrial lesion sets are the most effective treatment option for AF59. Patients with longstanding or symptomatic AF, young patients or those undergoing right heart surgery

The Cox maze IV procedure is performed with the patient on CPB with bicaval cannulation. Using blunt dissection, the right and left PVs are dissected. If the patient is in AF, they are cardioverted. Pacing thresholds are obtained from all PVs. The bipolar ablation is performed around the cuff of atrial tissue surrounding the right and left pulmonary veins. Pacing is used to confirm block from both the superior and inferior PVs. Following PVI, the right atrial lesions are performed with the heart beating. An incision is created in the right atrial appendage as shown in figure 3. The bipolar device is used to make a right atrial free wall lesion. Following this a vertical right atriotomy is made around 2cm from the free wall ablation that extends from the crista terminalis toward the intra-atrial septum. The incision is then extended superiorly toward the AV groove. Two cryolesions are placed at the tricuspid annulus using cryoprobe. The bipolar clamp is used to create linear ablation lines from the SVC down to the IVC. The SVC ablation is made as laterally as possible to avoid damage to the SA node. The left sided atrial lesions are performed through a standard left atriotomy. This extends superiorly onto the dome of the left atrium and inferiorly around the orifice of the right inferior pulmonary vein. A lesion is made with the bipolar RF device to create a connecting lesion between the left atrial incision inferiorly to the ablation line encircling left inferior pulmonary vein. In atria greater than 5cm in diameter, a second connecting ablation is placed from the superior aspect of the incision into the left superior pulmonary vein. Finally, a bipolar radiofrequency ablation line is performed from the inferior aspect of the left atrial incision across the mitral valve annulus at a point between the circumflex and right coronary artery circulation. A cryolesion is placed at the mitral valve annulus. The left atrial appendage is amputated and a bipolar RF ablation is performed between the amputated left atrial appendage and superior PV. The left atrial appendage is oversewn. The aorta is unclamped and the right atrial incision is closed. Patients with lone atrial fibrillation can choose between a catheter based approach or a minimally invasive surgical technique. Minimally invasive surgery to treat lone atrial fibrillation also can benefit patients who have a contraindication to warfarin, antiarrhythmic medications, or a history of cerebrovascular events. The procedure involves groin

Three general categories of lesion sets exist for the surgical treatment of AF in adults:

**6. Lesion sets for the surgical treatment of atrial fibrillation** 

 Pulmonary vein isolation Left atrial lesion set Biatrial lesion set

would benefit from this procedure60

sinus. The left atrium is exposed by an incision posterior to the interatrial groove close to the orifices of the right pulmonary veins. A number of incisions are made across the left atrium and the left atrial appendage is excised at its base. The incisions to the left atrium interatrial septum and right atrium are closed. Despite its complexity, the Cox-Maze III procedure became the gold standard for surgical treatment of AF. It has been performed in hundreds of patients and proven to be highly successful in ablating any form of AF irrespective of whether patients had concomitant heart disease or not.42,43 Although it adds to cardiopulmonary bypass and cardiac arrest time it does not increase the operative mortality.44,45

Sinus rhythm was reported in 97% at late follow-up and it was equally effective in patients with lone AF as those undergoing concomitant cardiac surgery.44,46 Similar results were reproduced by other institutions across the world.47,48Early postoperative AF is common following a maze procedure and usually abates by 3 months.44,46 In addition to restoring sinus rhythm the maze procedure is associated with additional clinical benefits for the patients. In those with mitral valve disease restoration of sinus rhythm improves survival. Risks for stroke, systemic thromboembolism and anticoagulant-related haemorrhage are also reduced.41,49The freedom from late stroke is likely to be from restoration of sinus rhythm as well as excision of the left atrial appendage, an integral part of the maze procedure.50

Despite the excellent results of the cut and sew maze procedure, few surgeons adopted the procedure due to its technical difficulty and is almost obsolete today. Advances in the understanding the pathophysiology of AF and newer ablation technologies fostered the development of novel strategies aimed at simplifying the procedure to make it more accessible to the average surgeon without compromising the results.

Use of ablative energy sources has enabled to replace most of Cox III incisions with a variety of energy sources including radiofrequency, cryoablation and high frequency ultrasound. The development of these technologies has rendered a technically difficult and timeconsuming operation easy for all cardiac surgeons to perform. Ablation technologies have also helped foster the development of less invasive procedures through a small incision or port. In order to replace the incision in AF surgery, ablation technology must meet several requirements. It must reliably produce transmural lesion either from the epicardial or endocardial surface to ensure bidirectional conduction block. It should also be safe and render AF surgery simpler and less time consuming to perform. It would also be adaptable to minimally invasive approach. Melby and colleagues51 described procedure that replaced with cut-and-sew lesions with bipolar radiofrequency lines as the Cox-Maze IV. In this technique, the atrial septal lesion was not performed and an independent isolation of the pulmonary veins was made with a connecting lesion. Although bipolar radiofrequency may reliably produce transmural lines and applied minimally invasively for pulmonary veins, it does not permit secure performance of connecting lines in the left atrial isthmus or inside the right atrium.53,54

Early follow-up suggests that the Cox-Maze IV procedure is similar in efficacy with 91% of patients having freedom from AF at 6 months.55 There was no operative mortality and the group had significantly shorter cross clamp time compared to the Cox Maze III group. Cox also suggested another simplified procedure to cure most patients of AF.56 This involved three essential lesions that include 1.an incision encircling the pulmonary veins, 2.left atrial isthmus and companion coronary sinus lesions and 3.right atrial isthmus lesion. This modified Cox-Maze procedure has been shown to be nearly as effective as the Cox-Maze III.57

sinus. The left atrium is exposed by an incision posterior to the interatrial groove close to the orifices of the right pulmonary veins. A number of incisions are made across the left atrium and the left atrial appendage is excised at its base. The incisions to the left atrium interatrial septum and right atrium are closed. Despite its complexity, the Cox-Maze III procedure became the gold standard for surgical treatment of AF. It has been performed in hundreds of patients and proven to be highly successful in ablating any form of AF irrespective of whether patients had concomitant heart disease or not.42,43 Although it adds to cardiopulmonary bypass and cardiac arrest time it does not increase the operative

Sinus rhythm was reported in 97% at late follow-up and it was equally effective in patients with lone AF as those undergoing concomitant cardiac surgery.44,46 Similar results were reproduced by other institutions across the world.47,48Early postoperative AF is common following a maze procedure and usually abates by 3 months.44,46 In addition to restoring sinus rhythm the maze procedure is associated with additional clinical benefits for the patients. In those with mitral valve disease restoration of sinus rhythm improves survival. Risks for stroke, systemic thromboembolism and anticoagulant-related haemorrhage are also reduced.41,49The freedom from late stroke is likely to be from restoration of sinus rhythm as well as excision of the left atrial appendage, an integral part of the maze

Despite the excellent results of the cut and sew maze procedure, few surgeons adopted the procedure due to its technical difficulty and is almost obsolete today. Advances in the understanding the pathophysiology of AF and newer ablation technologies fostered the development of novel strategies aimed at simplifying the procedure to make it more

Use of ablative energy sources has enabled to replace most of Cox III incisions with a variety of energy sources including radiofrequency, cryoablation and high frequency ultrasound. The development of these technologies has rendered a technically difficult and timeconsuming operation easy for all cardiac surgeons to perform. Ablation technologies have also helped foster the development of less invasive procedures through a small incision or port. In order to replace the incision in AF surgery, ablation technology must meet several requirements. It must reliably produce transmural lesion either from the epicardial or endocardial surface to ensure bidirectional conduction block. It should also be safe and render AF surgery simpler and less time consuming to perform. It would also be adaptable to minimally invasive approach. Melby and colleagues51 described procedure that replaced with cut-and-sew lesions with bipolar radiofrequency lines as the Cox-Maze IV. In this technique, the atrial septal lesion was not performed and an independent isolation of the pulmonary veins was made with a connecting lesion. Although bipolar radiofrequency may reliably produce transmural lines and applied minimally invasively for pulmonary veins, it does not permit secure performance of connecting lines in the left atrial isthmus or inside

Early follow-up suggests that the Cox-Maze IV procedure is similar in efficacy with 91% of patients having freedom from AF at 6 months.55 There was no operative mortality and the group had significantly shorter cross clamp time compared to the Cox Maze III group. Cox also suggested another simplified procedure to cure most patients of AF.56 This involved three essential lesions that include 1.an incision encircling the pulmonary veins, 2.left atrial isthmus and companion coronary sinus lesions and 3.right atrial isthmus lesion. This modified Cox-

Maze procedure has been shown to be nearly as effective as the Cox-Maze III.57

accessible to the average surgeon without compromising the results.

mortality.44,45

procedure.50

the right atrium.53,54

## **6. Lesion sets for the surgical treatment of atrial fibrillation**

Three general categories of lesion sets exist for the surgical treatment of AF in adults:


Pulmonary vein isolation is only an ideal choice for those who have new onset paroxysmal AF Lesions can be created using a variety of different approaches that include beating heart epicardial techniques or on pump endocardial approaches that use energy devices or the cut and sew technique. Pulmonary vein isolation can be achieved through either a single lesion encircling all pulmonary veins or two lesions encompassing the left and right pulmonary veins. Left atrial lesion sets are advised in patients with recent-onset or paroxysmal AF undergoing elective surgery with no justification to open the right atrium. This includes pulmonary vein isolation with the addition of linear lesions extending to the mitral annulus and left atrial appendage that is usually excised or excluded. This is because more than 90% of left atrial thrombi originate from the left atrial appendage in patients with non-rheumatic AF.58 Biatrial lesion sets are the most effective treatment option for AF59. Patients with longstanding or symptomatic AF, young patients or those undergoing right heart surgery would benefit from this procedure60

The Cox maze IV procedure is performed with the patient on CPB with bicaval cannulation. Using blunt dissection, the right and left PVs are dissected. If the patient is in AF, they are cardioverted. Pacing thresholds are obtained from all PVs. The bipolar ablation is performed around the cuff of atrial tissue surrounding the right and left pulmonary veins. Pacing is used to confirm block from both the superior and inferior PVs. Following PVI, the right atrial lesions are performed with the heart beating. An incision is created in the right atrial appendage as shown in figure 3. The bipolar device is used to make a right atrial free wall lesion. Following this a vertical right atriotomy is made around 2cm from the free wall ablation that extends from the crista terminalis toward the intra-atrial septum. The incision is then extended superiorly toward the AV groove. Two cryolesions are placed at the tricuspid annulus using cryoprobe. The bipolar clamp is used to create linear ablation lines from the SVC down to the IVC. The SVC ablation is made as laterally as possible to avoid damage to the SA node. The left sided atrial lesions are performed through a standard left atriotomy. This extends superiorly onto the dome of the left atrium and inferiorly around the orifice of the right inferior pulmonary vein. A lesion is made with the bipolar RF device to create a connecting lesion between the left atrial incision inferiorly to the ablation line encircling left inferior pulmonary vein. In atria greater than 5cm in diameter, a second connecting ablation is placed from the superior aspect of the incision into the left superior pulmonary vein. Finally, a bipolar radiofrequency ablation line is performed from the inferior aspect of the left atrial incision across the mitral valve annulus at a point between the circumflex and right coronary artery circulation. A cryolesion is placed at the mitral valve annulus. The left atrial appendage is amputated and a bipolar RF ablation is performed between the amputated left atrial appendage and superior PV. The left atrial appendage is oversewn. The aorta is unclamped and the right atrial incision is closed.

Patients with lone atrial fibrillation can choose between a catheter based approach or a minimally invasive surgical technique. Minimally invasive surgery to treat lone atrial fibrillation also can benefit patients who have a contraindication to warfarin, antiarrhythmic medications, or a history of cerebrovascular events. The procedure involves groin

Surgery for Atrial Fibrillation 265

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**7. References** 

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2003:32(5):291-299.

Fig. 3. Cox-Maze IV procedure

cannulation to connect the patient to CPB. The right sided lesions can be completed on a beating heart with or without cardiopulmonary support. After cross clamping the aorta, left sided lesions are created in a similar pattern to the Cox-Maze II procedure, creating a box lesion around all the pulmonary veins with a connecting lesion to the left atrial appendage and to the mitral valve isthmus. The left atrial orifice is closed from the endocardial side. When performed correctly, the results of the minimally invasive approach are excellent.61

Minimally invasive surgical techniques have been an area of interest as an alternative to catheter based pulmonary vein isolation. Bilateral thoracotomies or mini sternotomy can be used to isolate the pulmonary veins62,63. Its major advantage is that it can be performed in the absence of cardiopulmonary bypass and in many cases left atrial appendage disarticulation can also be offered. However, since AF does not always originate in the pulmonary veins this is not suitable in all patients, particularly those with non-paroxysmal AF.

Surgery for AF reduces medical costs successfully. When performed in conjunction with elective cardiac surgery it is cheaper and more effective than medical or catheter based therapy at a later time and cost effective in patients with a good prognosis64,65 In summary, surgery for AF has evolved during the previous 2 decades to include several different approaches, lesion sets and energy sources. All patients undergoing concomitant cardiac surgery with AF should undergo surgical treatment for their AF. Ablation technology has simplified the procedure to make it easy for all surgeons to adopt and pave way towards minimal access procedures.

### **7. References**

264 Special Topics in Cardiac Surgery

Superior vena cava

Right Atrial Appendage

Tricuspid Annulus

> Surgical Incision Radio-frequency Ablation Cryo Ablation

cannulation to connect the patient to CPB. The right sided lesions can be completed on a beating heart with or without cardiopulmonary support. After cross clamping the aorta, left sided lesions are created in a similar pattern to the Cox-Maze II procedure, creating a box lesion around all the pulmonary veins with a connecting lesion to the left atrial appendage and to the mitral valve isthmus. The left atrial orifice is closed from the endocardial side. When performed correctly, the results of the minimally invasive approach are excellent.61 Minimally invasive surgical techniques have been an area of interest as an alternative to catheter based pulmonary vein isolation. Bilateral thoracotomies or mini sternotomy can be used to isolate the pulmonary veins62,63. Its major advantage is that it can be performed in the absence of cardiopulmonary bypass and in many cases left atrial appendage disarticulation can also be offered. However, since AF does not always originate in the pulmonary veins this is not suitable in all patients, particularly those with non-paroxysmal

Inferior vena cava

Surgery for AF reduces medical costs successfully. When performed in conjunction with elective cardiac surgery it is cheaper and more effective than medical or catheter based therapy at a later time and cost effective in patients with a good prognosis64,65 In summary, surgery for AF has evolved during the previous 2 decades to include several different approaches, lesion sets and energy sources. All patients undergoing concomitant cardiac surgery with AF should undergo surgical treatment for their AF. Ablation technology has simplified the procedure to make it easy for all surgeons to adopt and pave way towards

Fig. 3. Cox-Maze IV procedure

Mitral Annulus

Left Atrial Appendage

minimal access procedures.

AF.


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**12** 

*Iran* 

Parisa Badiee

**Post-Cardiac Surgery Fungal Endocarditis** 

Infective endocarditis (IE) is a threatening disease associated with a high risk of morbidity and mortality. The most etiologic agents are the bacteria followed by fungi. Fungal Endocarditis (FE) is an uncommon occurrence and the most severe form of IE, however, its rate has increased in recent decades. The first report of FE after a mitral valve replacement was in 1964 (1) but there have been many cases reported in recent years indicating the importance of such infections (2-4). Fungal endocarditis accounts for 1.3% to 6% of all IE cases (5-8). Ranges between 1.7 to 3.8 per 100,000 person-years have been reported in different studies for mean annual incidence (5, 9). Increase in the number of cases of fungemia and FE has been seen during the last 2 decades (10, 11). Men are more at risk of infections than women (7, 12, 13), and younger persons (third to fourth decades of life) are in more risk factor. The incidence of FE varies based on the criteria and methods of diagnosis (5) and population under survey; in liver transplants (14) the incidence of FE after transplantation was 1.7%. The mortality rate was 72% (15) but is still high (about 50%) despite the treatments (7). In an international multicenter prospective cohort study that included 33 cases of *Candida* endocarditis treated between 2000 and 2005, the mortality rate was 30 % (16), and in post-surgical invasive aspergillosis (17) and *Aspergillus* endocarditis

the rate was too high (100%) even with combined medical and surgical therapy (2).

documented cases has been reported to range from 12% to 20% (21) or to 37.5% (22).

Fungi are important causes of prosthetic valve endocarditis, responsible for 1%–10% of these infections (18). Also, there are reports that fungi are responsible for 9.6% of the early cases of prosthetic valve endocarditis (60 days after the insertion of prosthesis) and for 4.3% of late cases (>60 days after the insertion of prosthesis) (19, 20). The incidence of FE in culture-

Many fungal species cause FE, of which the most important are *Candida albicans* 60%-67% and filamentous *Aspergillus* spp. 20–30% (ratio rate 2/1) (7, 15, 23), In addition, non-*albicans*  species of *Candida*, *Torulopsis glabrata, Candida tropicalis*, and other filamentus fungi like *Aspergillus* spp., *Curvularia genuculata, Hormondendrum dermatitidis, Mucoracae*, *Scopulariopsis* spp., *Trichosporon spp. and Blastoschizomyces capitatus* have been reported in the literature (10, 15, 22, 24, 25). In some studies, the most common etiologic agent was different, as in Rubinstein E et al. *Candida parapsilosis* accounts for half of the culture-documented patients, whereas *C. albicans* and *Candida stellatoidea* account for 12%-15% only (21)*. Pneumocystis jiroveci* caused fungal infection in 9% to 11% of all heart transplant recipients in the past, with a mortality rate of 11% to 38% (26) but with use of prophylaxis, the rate of this infection

**1. Introduction** 

has decreased.

*Professor Alborzi Clinical Microbiology Research Center,* 

*Shiraz University of Medical Sciences, Shiraz,* 

